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What changed in WHITE MOUNTAINS INSURANCE GROUP LTD's 10-K — 2024 vs 2025

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Paragraph-level year-over-year comparison of WHITE MOUNTAINS INSURANCE GROUP LTD's 2024 and 2025 10-K annual filings, covering the Business, Risk Factors, Legal Proceedings, Cybersecurity, MD&A and Market Risk sections. Every new, removed and edited paragraph is highlighted side-by-side so you can see exactly what management changed in the 2025 report.

+695 added−662 removedSource: 10-K (2026-02-27) vs 10-K (2025-02-28)

Top changes in WHITE MOUNTAINS INSURANCE GROUP LTD's 2025 10-K

695 paragraphs added · 662 removed · 520 edited across 8 sections

Item 1. Business

Business — how the company describes what it does

162 edited+45 added−37 removed154 unchanged
Biggest change“AA-” is the fourth highest, “A+” is the fifth highest, “A” is the sixth highest and “A-” is the seventh highest of 23 credit ratings assigned by Standard & Poor’s. 14 The following tables present the geographic distribution of HG Re’s insured portfolio as of December 31, 2024 and 2023: December 31, 2024 $ in Millions Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed California 891 $ 3,336.9 18.0 % Texas 1,156 2,940.7 15.9 Illinois 499 1,721.2 9.3 Pennsylvania 555 1,688.2 9.1 New York 421 866.3 4.7 New Jersey 212 712.7 3.9 Alabama 216 563.0 3.0 Florida 99 523.3 2.8 Ohio 197 494.1 2.7 Indiana 152 463.5 2.5 Other States 1,753 5,193.4 28.1 Total insured portfolio 6,151 $ 18,503.3 100.0 % December 31, 2023 $ in Millions Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed California 862 $ 3,233.6 19.5 % Texas 1,057 2,462.3 14.9 Pennsylvania 543 1,654.4 10.0 Illinois 487 1,562.4 9.4 New York 417 845.6 5.1 New Jersey 210 692.4 4.2 Alabama 212 489.8 3.0 Florida 92 475.3 2.9 Ohio 191 471.0 2.8 Indiana 145 377.9 2.3 Other States 1,550 4,310.5 25.9 Total insured portfolio 5,766 $ 16,575.2 100.0 % 15 The following table presents HG Re’s insured portfolio by issuer size of exposure as of December 31, 2024 and 2023: $ in Millions December 31, 2024 December 31, 2023 Original Par Value of Policies Assumed Per Issuer (1) Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Less than $1 million 2,796 $ 1,280.6 6.9 % 2,619 $ 1,212.1 7.3 % $1 to $2 million 1,260 1,798.8 9.7 1,205 1,711.7 10.3 $2 to $5 million 1,242 3,909.2 21.1 1,162 3,659.4 22.1 $5 to $10 million 492 3,430.3 18.5 466 3,251.3 19.6 $10 to $20 million 217 2,952.6 16.0 196 2,712.9 16.4 $20 to $50 million 121 3,697.8 20.0 101 3,018.2 18.2 Above $50m 23 1,434.0 7.8 17 1,009.6 6.1 Total insured portfolio 6,151 $ 18,503.3 100.0 % 5,766 $ 16,575.2 100.0 % (1) The original par value of policies assumed per issuer does not include refunded and re-issued deals.
Biggest changeThe following tables present the geographic distribution of HG Re’s insured portfolio as of December 31, 2025 and 2024: December 31, 2025 $ in Millions Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed California 908 $ 3,677.7 17.9 % Texas 1,268 3,388.7 16.5 % Illinois 529 1,909.4 9.3 % Pennsylvania 568 1,718.5 8.4 % New York 423 969.3 4.7 % New Jersey 218 772.3 3.8 % Alabama 221 612.3 3.0 % Ohio 209 600.4 2.9 % Florida 98 524.0 2.5 % Indiana 158 509.4 2.5 % Other States 1,917 5,877.9 28.5 % Total insured portfolio 6,517 $ 20,559.9 100.0 % 15 December 31, 2024 $ in Millions Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed California 891 $ 3,336.9 18.0 % Texas 1,156 2,940.7 15.9 Illinois 499 1,721.2 9.3 Pennsylvania 555 1,688.2 9.1 New York 421 866.3 4.7 New Jersey 212 712.7 3.9 Alabama 216 563.0 3.0 Florida 99 523.3 2.8 Ohio 197 494.1 2.7 Indiana 152 463.5 2.5 Other States 1,753 5,193.4 28.1 Total insured portfolio 6,151 $ 18,503.3 100.0 % The following table presents HG Re’s insured portfolio by issuer size of exposure as of December 31, 2025 and 2024: $ in Millions December 31, 2025 December 31, 2024 Original Par Value of Policies Assumed Per Issuer (1) Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Number of Risks Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Less than $1 million 2,981 $ 1,361.8 6.6 % 2,796 $ 1,280.6 6.9 % $1 to $2 million 1,284 1,850.0 9.0 1,260 1,798.8 9.7 $2 to $5 million 1,313 4,175.3 20.3 1,242 3,909.2 21.1 $5 to $10 million 538 3,800.1 18.5 492 3,430.3 18.5 $10 to $20 million 239 3,319.5 16.1 217 2,952.6 16.0 $20 to $50 million 131 4,019.5 19.6 121 3,697.8 20.0 Above $50m 31 2,033.7 9.9 23 1,434.0 7.8 Total insured portfolio 6,517 $ 20,559.9 100.0 % 6,151 $ 18,503.3 100.0 % (1) The original par value of policies assumed per issuer does not include refunded and re-issued deals.
The remaining capital was provided by third-party investors. During the fourth quarter of 2024, Ark renewed Outrigger Re Ltd. for the 2025 underwriting year with $230 million of capital. White Mountains’s total commitment was $150 million, of which $130 million was rolled over from its commitment to the 2024 underwriting year. The remaining capital was provided by third-party investors.
During the fourth quarter of 2024, Ark renewed Outrigger Re Ltd. for the 2025 underwriting year with $230 million of capital. White Mountains’s total commitment was $150 million, of which $130 million was rolled over from its commitment to the 2024 underwriting year. The remaining capital was provided by third-party investors.
The nature of delegated underwriting naturally increases the risk of underwriting, through the ability of third parties being able to bind Ark to risks without detailed review of the risk involved. This risk is mitigated through the application of strict guidelines, managed by a dedicated team within the Ark compliance department.
The nature of delegated underwriting naturally increases the risk of underwriting, through the ability of third parties being able to bind Ark to risks without detailed review of the risk involved. This risk is mitigated through the application of strict underwriting guidelines, managed by a dedicated team within the Ark compliance department.
Outside of natural catastrophe losses, Ark has exposure to non-natural or man-made large losses. The current largest exposures are cyber, offshore energy production platforms, terrorism events, war and war-like actions and political risk. Ark uses data from clients and combines this with accumulation tools and PML assessments to obtain potential loss scenarios.
Outside of natural catastrophe losses, Ark has exposure to non-natural or man-made large losses. The current largest exposures are cyber, offshore energy production platforms, aviation, terrorism events, war and war-like actions and political risk. Ark uses data from clients and combines this with accumulation tools and PML assessments to obtain potential loss scenarios.
All else being equal, pricing is generally higher when interest rates are higher, credit spreads are wider, BAM’s trading value is higher relative to competitors and the capture rate is higher. Insured Portfolio Under the FLRT, HG Re provides first-loss reinsurance protection of up to 15%-of-par outstanding for each policy assumed from BAM.
All else being equal, pricing is generally higher when interest rates are higher, credit spreads are wider, BAM’s trading value is higher relative to competitors and the capture rate is higher. 13 Insured Portfolio Under the FLRT, HG Re provides first-loss reinsurance protection of up to 15%-of-par outstanding for each policy assumed from BAM.
Reinsurance can provide a ceding company with additional underwriting capacity by permitting it to accept larger risks and underwrite a greater number of risks without increasing its capital as much as would be the case without reinsurance. Reinsurers themselves, may also purchase reinsurance, which is known as retrocessional reinsurance to cover risks assumed from ceding companies.
Reinsurance can provide a ceding company with additional underwriting capacity by permitting it to accept larger risks and underwrite a greater number of risks without increasing its capital as much as would be the case without reinsurance. Reinsurers may also purchase reinsurance for themselves, which is known as retrocessional reinsurance, to cover risks assumed from ceding companies.
General The operations of ASML, Ark’s wholly-owned Lloyd’s managing agent, are subject to oversight by Lloyd’s, through the Lloyd’s Council. ASML’s business plan for the Syndicates, including maximum stamp capacity, requires annual approval by Lloyd’s. Stamp capacity is a measure of the amount of net premium (premiums written less acquisition costs) that a syndicate is authorized by Lloyd’s to write.
General The operations of ASML, Ark’s wholly-owned Lloyd’s managing agent, are subject to oversight by Lloyd’s, through the Lloyd’s Council. ASML’s business plan for the Syndicates, including maximum stamp capacity, requires annual approval from Lloyd’s. Stamp capacity is a measure of the amount of net premium (premiums written less acquisition costs) that a syndicate is authorized by Lloyd’s to write.
Restrictions on Dividends, Distributions and Reductions of Capital As a Class 4 insurer, GAIL is prohibited from declaring or paying any dividends if in breach of the required minimum solvency margin or minimum liquidity ratio (the “Relevant Margins”) or if the declaration or payment of such dividend would cause the insurer to fail to meet the Relevant Margins.
Restrictions on Dividends and Reductions of Capital As a Class 4 insurer, GAIL is prohibited from declaring or paying any dividends if in breach of the required minimum solvency margin or minimum liquidity ratio (the “Relevant Margins”) or if the declaration or payment of such dividend would cause the insurer to fail to meet the Relevant Margins.
Ark competes with other Lloyd’s syndicates, London market participants and major U.S., Bermuda, European and other international insurance and reinsurance companies. The significant competitive factors for most products are price, terms and conditions, broker relationships, underwriting service, rating agency financial strength rating and claims service.
Ark competes with other Lloyd’s syndicates, London market participants and major U.S., Bermuda, European and other international insurance and reinsurance companies. The significant competitive factors for most products are price, terms and conditions, broker relationships, underwriting service, financial strength rating and claims service.
During the fourth quarter of 2023 and 2024, Ark renewed its collateralized quota share agreements with Outrigger Re Ltd., a Bermuda special purpose insurer, covering Ark’s Bermuda global property catastrophe excess of loss portfolio written in the 2024 and 2025 underwriting years, respectively.
During the fourth quarter of 2023, 2024 and 2025, Ark renewed its collateralized quota share agreements with Outrigger Re Ltd., a Bermuda special purpose insurer, covering Ark’s Bermuda global property catastrophe excess of loss portfolio written in the 2024, 2025 and 2026 underwriting years, respectively.
White Mountains’s property and casualty insurance and reinsurance business is conducted through its subsidiary Ark Insurance Holdings Limited and its subsidiaries (collectively, “Ark”) and Outrigger Re Ltd. Segregated Account 2023-1 (“WM Outrigger Re”) (collectively with Ark, “Ark/WM Outrigger”). White Mountains’s municipal bond reinsurance business is conducted through its subsidiary HG Global Ltd. and its reinsurance subsidiary HG Re Ltd.
White Mountains’s property and casualty insurance and reinsurance business is conducted through its subsidiary Ark Insurance Holdings Limited and its subsidiaries (collectively, “Ark”) and Outrigger Re Ltd. Segregated Account 2023-1 (“WM Outrigger Re”) (collectively with Ark, “Ark/WM Outrigger”). White Mountains’s municipal bond guarantee reinsurance business is conducted through its subsidiary HG Global Ltd. and its reinsurance subsidiary HG Re Ltd.
Where such laws apply to us, there can be no effective change in our control (or in the control of some or our subsidiaries) unless the person seeking to acquire control has filed a statement with the regulators and obtained prior approval for the proposed change.
Where such laws apply, there can be no effective change in our control (or in the control of some or our subsidiaries) unless the person seeking to acquire control has filed a statement with the regulators and obtained prior approval for the proposed change.
XOLT HG Re is also party to an excess of loss reinsurance agreement (the “XOLT”) with BAM. Under the XOLT, HG Re provides last-dollar protection for exposures on municipal bonds insured by BAM in excess of the NYDFS single issuer limits.
XOLT HG Re is also party to an excess of loss reinsurance agreement (the “XOLT”) with BAM under which HG Re provides last-dollar protection for exposures on municipal bonds insured by BAM in excess of the NYDFS single issuer limits.
Ark incorporates the physical risk of climate change in its underwriting process through sensitivity and stress testing of its catastrophe models, including increased frequency of U.S. windstorms and the implications of storm surge. 8 Ark licenses third-party global property catastrophe models from Risk Management Solutions Inc. and Karen Clark & Company, as well as utilizing its own proprietary models to calculate expected probable maximum loss estimates (“PML”) from various property and non-property catastrophe scenarios.
Ark incorporates the physical risk of climate change in its underwriting process through sensitivity and stress testing of its catastrophe models, including increased frequency of U.S. windstorms and the implications of storm surge. 8 Ark licenses third-party global property catastrophe models from Risk Management Solutions Inc. and Karen Clark & Company, as well as utilizes its own proprietary models to calculate expected probable maximum loss (“PML”) estimates from various property and non-property catastrophe scenarios.
The Company believes it complies with all of the applicable laws and regulations pertaining to economic substance that would have a material effect on its financial condition and results of operations in the event of non-compliance. 25 United Kingdom PRA and FCA Regulation As an insurer in the United Kingdom, Ark is dual-regulated by the Financial Conduct Authority (the “FCA”) and the Prudential Regulation Authority (the “PRA”) (collectively, the “U.K.
The Company believes it complies with all of the applicable laws and regulations pertaining to economic substance that would have a material effect on its financial condition and results of operations in the event of non-compliance. 26 United Kingdom PRA and FCA Regulation As an insurer in the United Kingdom, Ark is dual-regulated by the Financial Conduct Authority (the “FCA”) and the Prudential Regulation Authority (the “PRA”) (collectively, the “U.K.
Investment Regulation Kudu Investment Holdings, LLC, a subsidiary of Kudu, is an investment adviser that is registered with the SEC under Section 203 of the United States Investment Advisers Act of 1940. 22 Bermuda Insurance Regulation The Insurance Act 1978 of Bermuda and related regulations, as amended (the “Insurance Act”), regulates the insurance business of HG Re, a special purpose insurer, GAIL, Ark’s wholly-owned Class 4 insurance and reinsurance company and Outrigger Re Ltd., a special purpose insurer.
Investment Regulation Kudu Investment Holdings, LLC, a subsidiary of Kudu, is an investment adviser that is registered with the SEC under Section 203 of the United States Investment Advisers Act of 1940. 23 Bermuda Insurance Regulation The Insurance Act 1978 of Bermuda and related regulations, as amended (the “Insurance Act”), regulates the insurance business of HG Re, a special purpose insurer, GAIL, Ark’s wholly-owned Class 4 insurance and reinsurance company and Outrigger Re Ltd., a special purpose insurer.
Lloyd’s prescribes, in respect of its managing agents and corporate and individual members (“Members”), certain minimum standards relating to their management and control, solvency and various other requirements.
Lloyd’s prescribes, in respect of its managing agents and corporate and individual members, certain minimum standards relating to their management and control, solvency and various other requirements.
Ark Syndicate Management Limited (“ASML”), Ark’s wholly-owned Lloyd’s managing agent, oversees the underwriting of the Syndicates. The Syndicates underwrite a diversified portfolio of insurance and reinsurance, including property, specialty, marine & energy, casualty and accident & health. Syndicate 4020 commenced underwriting on April 1, 2007, Syndicate 3902 on January 1, 2017 and ACSN 3832 on July 1, 2024.
Ark Syndicate Management Limited (“ASML”), Ark’s wholly-owned Lloyd’s managing agent, oversees the underwriting of the Syndicates. The Syndicates underwrite a diversified portfolio of insurance and reinsurance product lines, including property, specialty, marine & energy, casualty and accident & health. Syndicate 4020 commenced underwriting on April 1, 2007, Syndicate 3902 on January 1, 2017 and ACSN 3832 on July 1, 2024.
Climate change, which is characterized by higher temperatures, sea level rise and more extreme weather events including droughts, heavy storms, wildfires and stronger hurricanes, increases the frequency and severity of certain major natural catastrophes. There is also a growing threat of cyber catastrophes due to the increasing interconnectivity of global systems.
Climate change, which is characterized by higher temperatures, sea level rise and more extreme weather events including droughts, heavy storms, wildfires and stronger hurricanes, increases the frequency and severity of certain major natural catastrophes. There is also a growing threat of cyber catastrophes due to the increasing interconnectivity of global systems and artificial intelligence.
See Note 6 — “Third-party Reinsurance” on page F- 45 for a discussion of Ark’s top reinsurers. Ark’s Loss and LAE Reserves Ark establishes loss and LAE reserves that are estimates of amounts needed to pay claims and related expenses in the future for insured events that have already occurred, including both reported and unreported claims.
See Note 6 — “Third-Party Reinsurance” on page F- 47 for a discussion of Ark’s top reinsurers. Ark’s Loss and LAE Reserves Ark establishes loss and LAE reserves that are estimates of amounts needed to pay claims and related expenses in the future for insured events that have already occurred, including both reported and unreported claims.
If fully earned, these shares would represent an additional 12.3% of the shares outstanding as of December 31, 2024. 2 WM Outrigger Re During the fourth quarter of 2022, Ark sponsored the formation of Outrigger Re Ltd., a Bermuda company registered as a special purpose insurer and segregated accounts company, to provide reinsurance capacity to Ark.
If fully earned, these shares would represent an additional 12.3% of the shares outstanding as of December 31, 2025. 2 WM Outrigger Re During the fourth quarter of 2022, Ark sponsored the formation of Outrigger Re Ltd., a Bermuda company registered as a special purpose insurer and segregated accounts company, to provide reinsurance capacity to Ark.
As special purpose insurers, HG Re and Outrigger Re Ltd. are not subject to this requirement. 23 Minimum Solvency Margin As a general business insurer, GAIL is required to maintain statutory assets in excess of its statutory liabilities by an amount, equal to or greater than the prescribed minimum solvency margin.
As special purpose insurers, HG Re and Outrigger Re Ltd. are not subject to this requirement. 24 Minimum Solvency Margin As a general business insurer, GAIL is required to maintain statutory assets in excess of its statutory liabilities by an amount, equal to or greater than the prescribed minimum solvency margin.
An excess of loss treaty is an arrangement whereby a reinsurer assumes losses that exceed a specific retention of loss by the ceding company.
An excess of loss reinsurance treaty is an arrangement whereby a reinsurer assumes losses that exceed a specific retention of loss by the ceding company.
Ark’s two largest natural catastrophe PML zones on a per occurrence basis for a 1-in-250 year event as of January 2025, as measured on a net after-tax exposure basis, are U.S. windstorm and U.S. earthquake. The net after-tax exposure is net of amounts ceded to reinsurers and reinstatement premiums.
Ark’s two largest natural catastrophe PML zones on a per occurrence basis for a 1-in-250 year event, as measured on a net after-tax exposure basis, are U.S. windstorm and U.S. earthquake. The net after-tax exposure is net of amounts ceded to reinsurers and reinstatement premiums.
Specie is the transit and storage of high value goods including semi-precious and precious metals. Marine & energy liabilities consists of liability risks arising from doing business in their respective industries including liabilities arising from pollution and damage covered by protection and indemnity clubs, including for example the International Group of Protection & Indemnity Clubs.
Specie is the transit and storage of high value goods including semi-precious and precious metals. Marine & energy liabilities consist of liability risks arising from doing business in their respective industries including liabilities arising from pollution and damage covered by protection and indemnity clubs, including for example the International Group of Protection & Indemnity Clubs.
As of February 27, 2025, each of Lloyd’s Syndicates 4020 and 3902 benefits from the financial strength rating of “A+/stable” by A.M. Best Company, Inc. (“A.M. Best”) and “AA-/stable” by Standard & Poor’s assigned to the Lloyd’s marketplace. “A+” is the second highest of 16 financial strength ratings assigned by A.M.
As of February 27, 2026, each of Lloyd’s Syndicates 4020 and 3902 benefits from the financial strength rating of “A+/stable” by A.M. Best Company, Inc. (“A.M. Best”) and “AA-/stable” by Standard & Poor’s assigned to the Lloyd’s marketplace. “A+” is the second highest of 16 financial strength ratings assigned by A.M.
Regulators”). The PRA currently has ultimate responsibility for the prudential supervision of financial services in the U.K. The FCA has responsibility for market conduct regulation. The U.K. Regulators regulate insurers, insurance intermediaries and Lloyd’s. Both the PRA and FCA have substantial powers of intervention in relation to regulated firms.
Regulators”). The PRA currently has ultimate responsibility for the prudential supervision of financial services in the United Kingdom. The FCA has responsibility for market conduct regulation. The U.K. Regulators regulate insurers, insurance intermediaries and Lloyd’s. Both the PRA and FCA have substantial powers of intervention in relation to regulated firms.
In states with file-and-use laws, the insurer does not have to wait for the regulator’s approval to use a rate, but the rate must be filed with the regulatory authority prior to being used. In states with use-and-file laws, the insurer must file rates within a certain period of time after the insurer begins to use them.
In states with file-and-use laws, the insurer does not have to wait for the regulator’s approval to use a rate, but the rate must be filed with the regulatory authority prior to being used. In states with use-and-file laws, the insurer must file rates within a certain period after the insurer begins to use them.
Kudu seeks to provide its solutions across a diverse mix of investment strategies and asset classes in the middle market. Kudu’s average capital deployment to date has been approximately $37 million, with a range from $14 million to $81 million.
Kudu seeks to provide its solutions across a diverse mix of investment strategies and asset classes in the middle market. Kudu’s average capital deployment to date has been approximately $39 million, with a range from $14 million to $81 million.
BAM may work with other insurers, municipal bondholders and/or interested parties on remediation efforts, as applicable. 16 KUDU Overview Kudu provides capital solutions for boutique asset and wealth managers for a variety of purposes including generational ownership transfers, management buyouts, acquisition and growth finance and legacy partner liquidity. Kudu also provides strategic assistance to investees from time to time.
BAM may work with other insurers, municipal bondholders and/or interested parties on remediation efforts, as applicable. 16 KUDU Overview Kudu provides capital solutions for boutique asset and wealth managers for a variety of purposes including generational ownership transfers, management buyouts, acquisition and growth finance and legacy partner liquidity. Kudu also provides strategic advice to managers from time to time.
Ark operates an underwriting controls framework which includes individual underwriting authorities, continual quality monitoring and peer review of risks. The framework aims to ensure a high quality of underwriting through monitoring of pricing and rate change, contract certainty and appropriate terms and conditions.
Ark operates an underwriting controls framework which includes individual underwriting authorities, continuous quality monitoring and peer review of risks. The framework aims to ensure a high quality of underwriting through monitoring of pricing and rate change, contract certainty and appropriate terms and conditions.
White Mountains believes that Bamboo is in compliance with all applicable laws and regulations pertaining to its business that would have a material effect on its financial condition or results of operations in the event of non-compliance.
White Mountains believes that Distinguished is in compliance with all applicable laws and regulations pertaining to its business that would have a material effect on its financial condition or results of operations in the event of non-compliance.
Ark’s property reinsurance business is underwritten on a worldwide basis with particular focus on risks in the United States, Europe and Asia. Ark also writes structured property business, which provides reinsurance capacity to primary fronting insurance companies, net after inuring reinsurance, with a limited downside risk profile that is managed through aggregated collateralized limits.
Ark’s property reinsurance business is underwritten on a worldwide basis with particular focus on risks in the United States and Europe. Ark also underwrites structured property business, which provides reinsurance capacity to primary fronting insurance companies, net after inuring reinsurance, with a limited downside risk profile that is managed through aggregated collateralized limits.
Ark prices property catastrophe contracts using its own proprietary models that can take inputs from third-party software and other data as appropriate. For business that Ark determines to have exposure to catastrophic perils, as part of its underwriting process, it models and evaluates the exposure to assess whether there is an appropriate premium charged for the exposure assumed.
Ark prices property catastrophe contracts using its own proprietary models, utilizing inputs from third-party software and other data as appropriate. For business that Ark determines to have exposure to catastrophic perils, as part of its underwriting process, it models and evaluates the exposure to assess whether there is an appropriate premium charged for the exposure assumed.
As of December 31, 2024, the XOLT is subject to an aggregate limit equal to the lesser of $125 million or the assets held in the supplemental collateral trust (the “Supplemental Trust”) at any point in time.
As of December 31, 2025, the XOLT is subject to an aggregate limit equal to the lesser of $125 million or the assets held in the supplemental collateral trust (the “Supplemental Trust”) at any point in time.
Additionally, a company may also face penalties, restriction or regulation of its business activities and may be struck off as a registered entity in Bermuda for failure to satisfy economic substance requirements.
Additionally, a company may also face penalties, restrictions or regulation of its business activities and may be struck off as a registered entity in Bermuda for failure to satisfy economic substance requirements.
As a segregated account, the solvency test for the declaration of dividends and distributions is evaluated based upon the solvency of WM Outrigger Re, rather than the solvency of Outrigger Re Ltd. as a whole. 24 Insurance Code of Conduct and Insurance Sector Operational Cyber Risk Management Code of Conduct All Bermuda insurers are required to comply with the BMA’s Insurance Code of Conduct, which establishes duties, requirements and standards to be complied with to ensure each insurer implements sound corporate governance, risk management and internal controls.
The solvency test for the declaration of dividends by WM Outrigger Re, as a segregated account, is evaluated based upon the solvency of WM Outrigger Re, rather than the solvency of Outrigger Re Ltd. as a whole. 25 Insurance Code of Conduct and Insurance Sector Operational Cyber Risk Management Code of Conduct All Bermuda insurers are required to comply with the BMA’s Insurance Code of Conduct, which establishes duties, requirements and standards to be complied with to ensure each insurer implements sound corporate governance, risk management and internal controls.
RATINGS Insurance companies are evaluated by various rating agencies in order to measure each company’s financial strength. Higher ratings generally indicate financial stability and a stronger ability to pay claims. White Mountains believes that strong ratings are important factors in the marketing and sale of insurance products and services to agents, consumers and ceding companies.
RATINGS Insurance companies are evaluated by various rating agencies in order to measure each company’s financial strength. Higher ratings generally indicate stronger financial stability and claims paying ability. White Mountains believes that strong ratings are important factors in the marketing and sale of insurance products and services to agents, consumers and ceding companies.
The 2024 BSCR must be filed with the BMA before April 30, 2025; at this time, we believe GAIL will exceed the minimum amount required to be maintained under Bermuda law.
The 2025 BSCR must be filed with the BMA before April 30, 2026; at this time, we believe GAIL will exceed the minimum amount required to be maintained under Bermuda law.
See “ CRITICAL ACCOUNTING ESTIMATES — Loss and LAE Reserves ” on page 85 and Note 5 — “Loss and Loss Adjustment Expense Reserves ” on page F- 34 for a full discussion regarding Ark’s loss reserving process. 10 HG GLOBAL Overview The HG Global segment consists of HG Global and, prior to its deconsolidation on July 1, 2024, the consolidated results of Build America Mutual Assurance Company (“BAM”).
See “ CRITICAL ACCOUNTING ESTIMATES — Loss and LAE Reserves ” on page 90 and Note 5 — “Loss and Loss Adjustment Expense Reserves ” on page F- 36 for a full discussion regarding Ark’s loss reserving process. 10 HG GLOBAL Overview The HG Global segment consists of HG Global and, prior to its deconsolidation on July 1, 2024, the consolidated results of Build America Mutual Assurance Company (“BAM”).
Specialty Ark’s specialty business is underwritten on both an insurance and reinsurance basis covering a range of individual risks and treaties primarily including aviation, space, political and credit, cyber, terrorism and political violence, nuclear, fine art & specie, surety and mortgage. Ark’s specialty insurance and reinsurance business is underwritten on a worldwide basis.
Specialty Ark’s specialty business is underwritten on both an insurance and reinsurance basis covering a range of individual risks and treaties primarily including aviation, contingency, cyber, fine art & specie, mortgage, nuclear, political and credit, space, surety as well as terrorism and political violence. Ark’s specialty insurance and reinsurance business is underwritten on a worldwide basis.
Ark estimates its largest net after-tax loss from non-natural/man-made loss scenarios to be approximately 10% of total tangible capital. 9 WM Outrigger Re WM Outrigger Re has exposure to losses caused by unpredictable catastrophic events including natural and other disasters all over the world such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis, severe weather and infrastructure failures.
Ark estimates its largest net after-tax loss from non-natural/man-made loss scenarios to be less than 10% of its tangible capital. 9 WM Outrigger Re WM Outrigger Re has exposure to losses caused by unpredictable catastrophic events including natural and other disasters all over the world such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis, severe weather and related infrastructure failures.
Kudu prioritizes the private capital segment as the underlying clients of these firms tend to be locked-up for an extended period, which can provide stability of revenues in a potential market downturn. Kudu seeks to diversify geographically.
Kudu prioritizes the private capital segment as the underlying clients of these firms tend to be locked-up for an extended period, which can provide stability of revenues in a potential market downturn.
In either case, the ECR shall at all times equal or exceed the insurer’s minimum solvency margin and may be adjusted in circumstances where the BMA concludes that the insurer’s risk profile deviates significantly from the assumptions underlying its ECR or the insurer’s assessment of its risk management policies and practices used to calculate the ECR applicable to it.
The ECR must at all times equal or exceed the insurer’s minimum solvency margin and may be adjusted in circumstances where the BMA concludes that the insurer’s risk profile deviates significantly from the assumptions underlying its ECR or the insurer’s assessment of its risk management policies and practices used to calculate the ECR applicable to it.
Any entity that must satisfy economic substance requirements but fails to do so could face automatic disclosure to competent authorities in the EU of the information filed by the entity with the Bermuda Registrar of Companies in connection with the economic substance requirements.
Any entity that must satisfy economic substance requirements but fails to do so could face automatic disclosure to competent authorities in the European Union of the information filed by the entity with the Bermuda Registrar of Companies in connection with the economic substance requirements.
Kudu’s capital was deployed at an average gross cash yield at inception of 9.6% based on expected cash in the first year following deployment. Kudu’s philosophy is to partner with asset and wealth management firms that exhibit strong cash flow generation and growth.
Since inception, Kudu’s capital was deployed at an initial average gross cash yield of 9.3% based on expected cash in the first year following deployment. Kudu’s philosophy is to partner with asset and wealth management firms that exhibit strong cash flow generation and growth.
Settlements for casualty/liability coverages can extend for long periods of time as claims are often reported and ultimately paid or settled years after the related loss events occur. Ark has recently added, and expects to continue to add, new business to its portfolio, as it focuses on profitable business opportunities while carefully managing underwriting risk.
Settlements for casualty/liability coverages can extend for long periods of time as claims are often reported and ultimately paid or settled years after the related loss events occur. Ark has recently added new products and lines of business to its portfolio, as it focuses on profitable business opportunities while carefully managing underwriting risk.
HG Global’s total equity attributable to White Mountains’s common shareholders after intercompany eliminations related to preferred dividends payable to White Mountains and intercompany debt was $729 million and $779 million as of December 31, 2024 and 2023. As of December 31, 2024 and 2023, White Mountains owned 96.9% of HG Global’s preferred equity and 88.4% of its common equity.
HG Global’s total equity attributable to White Mountains’s common shareholders after intercompany eliminations related to preferred dividends payable to White Mountains and intercompany debt was $756 million and $729 million as of December 31, 2025 and 2024. As of December 31, 2025 and 2024, White Mountains owned 96.9% of HG Global’s preferred equity and 88.4% of its common equity.
White Mountains invests in fixed maturity investments that are attractively priced in relation to their investment risks and actively manages the average duration of the fixed income portfolio. As of December 31, 2024, the fixed income portfolio duration, including short-term investments, was 1.9 years.
White Mountains invests in fixed maturity investments that are attractively priced in relation to their investment risks and actively manages the average duration of the fixed income portfolio. As of December 31, 2025, the fixed income portfolio duration, including short-term investments, was 1.5 years.
As of December 31, 2024 and 2023, the fair value of these interests totaled $49 million and $40 million. 20 INVESTMENTS White Mountains’s investment philosophy is to maximize long-term, after-tax total returns while taking prudent levels of risk and maintaining a diversified portfolio, subject to White Mountains’s investment guidelines and various regulatory restrictions.
As of December 31, 2025 and 2024, the fair value of these interests totaled $58 million and $49 million. INVESTMENTS White Mountains’s investment philosophy is to maximize long-term, after-tax total returns while taking prudent levels of risk and maintaining a diversified portfolio, subject to White Mountains’s investment guidelines and various regulatory restrictions.
The Regulation 114 Trust balance as of December 31, 2024 and 2023 was $352 million and $342 million, which consisted of cash, investments and accrued investment income. The Supplemental Trust target balance is $603 million, less the amount of cash and securities in the Regulation 114 Trust in excess of its target balance (the “Supplemental Trust Target Balance”).
The Regulation 114 Trust balance as of December 31, 2025 and 2024 was $399 million and $352 million, which consisted of cash, investments and accrued investment income. The Supplemental Trust target balance is $603 million, less the amount of cash and securities in the Regulation 114 Trust in excess of its target balance (the “Supplemental Trust Target Balance”).
As of December 31, 2024 and 2023, White Mountains owned 72.1% and 72.0% of Ark on a basic shares outstanding basis (61.9% and 61.9% after taking account of management’s equity incentives) and reported $410 million and $337 million of noncontrolling interests related to Ark. The remaining shares are owned by current and former employees of Ark.
As of December 31, 2025 and 2024, White Mountains owned 72.1% of Ark on a basic shares outstanding basis (61.9% after taking account of management’s equity incentives) and reported $465 million and $410 million of noncontrolling interests related to Ark. The remaining shares are owned by current and former employees of Ark.
The minimum solvency margin that must be maintained by a Class 4 insurer is the greater of (i) $100 million, (ii) 50% of net premiums written (with a credit for reinsurance ceded not exceeding 25% of gross premiums), (iii) 15% of net aggregate loss and loss expense provisions and other insurance reserves or (iv) 25% of the ECR, which is established by reference to the BSCR model.
The minimum solvency margin that must be maintained by a Class 4 insurer is the greater of (i) $100 million, (ii) 50% of net premiums written (with a credit for reinsurance ceded not exceeding 25% of gross premiums), (iii) 15% of net aggregate loss and loss expense provisions and other insurance reserves or (iv) 25% of the ECR.
Aviation Aviation insurance primarily covers airlines and general aviation for loss of, or damage to, aircraft hull and ensuing passenger and third-party liability. Perils include war and war-like actions such as terrorism. Additionally, liability arising out of non-aircraft operations such as hangars and airports may be covered.
Aviation Aviation insurance primarily covers airlines and general aviation for loss of, or damage to, aircraft hull and ensuing passenger and third-party liability. Perils include war and war-like actions such as terrorism, hijacking, confiscation, expropriation, nationalization and deprivation. Additionally, liability arising out of non-aircraft operations such as hangars and airports may be covered.
As of December 31, 2024, White Mountains conducted its business primarily in five areas: property and casualty insurance and reinsurance, municipal bond reinsurance, capital solutions for asset and wealth management firms, property and casualty insurance distribution and other operations.
As of December 31, 2025, White Mountains conducted its business primarily in five areas: property and casualty insurance and reinsurance, municipal bond guarantee reinsurance, capital solutions for asset and wealth management firms, specialty insurance distribution and other operations.
As of December 31, 2024, Kudu’s asset and wealth management firms had combined assets under management of approximately $125 billion, spanning a range of asset classes including real estate, wealth management, hedge funds, private equity and alternative credit strategies.
As of December 31, 2025, Kudu’s asset and wealth management firms had combined assets under management of approximately $153 billion, spanning a range of asset classes including real estate, wealth management, hedge funds, private equity and alternative credit strategies.
If a Member of Lloyd’s is unable to pay its debts to policyholders, the Member may obtain financial assistance from the Lloyd’s Central Fund, which in many respects acts as an equivalent to a state guaranty fund in the U.S.
If a member of Lloyd’s is unable to pay its debts to policyholders, the member may obtain financial assistance from the Lloyd’s Central Fund, which in many respects acts as an equivalent to a state guaranty fund in the United States.
Best and “AA-” is the fourth highest of 23 financial strength ratings assigned by Standard & Poor’s. As of February 27, 2025, Ark’s financial strength rating was “A/stable” by A.M. Best. “A” is the third highest of 16 financial strength ratings assigned by A.M. Best.
Best and “AA-” is the fourth highest of 23 financial strength ratings assigned by Standard & Poor’s. As of February 27, 2026, GAIL’s financial strength rating was “A/stable” by A.M. Best. “A” is the third highest of 16 financial strength ratings assigned by A.M. Best.
Geographic Concentration The following table shows Ark’s gross written premiums by geographic region based on the location of Ark’s underwriting offices for the years ended December 31, 2024, 2023 and 2022: Millions Year Ended December 31, Gross written premiums by country 2024 2023 2022 United Kingdom $ 1,229.5 $ 1,027.8 $ 833.4 Bermuda 977.5 870.6 618.6 Total $ 2,207.0 $ 1,898.4 $ 1,452.0 6 Marketing and Distribution Ark offers its products and services through a network of brokers, MGAs and reinsurance intermediaries (collectively, “insurance and reinsurance intermediaries”).
Geographic Concentration The following table shows Ark’s gross written premiums by geographic region based on the location of Ark’s underwriting offices for the years ended December 31, 2025, 2024 and 2023: Millions Year Ended December 31, Gross written premiums by country 2025 2024 2023 United Kingdom $ 1,404.7 $ 1,229.5 $ 1,027.8 Bermuda 1,152.5 977.5 870.6 Total $ 2,557.2 $ 2,207.0 $ 1,898.4 6 Marketing and Distribution Ark offers its products and services through a network of brokers, MGAs and reinsurance intermediaries (collectively, “insurance and reinsurance intermediaries”).
While Bamboo is not an insurer, and thus not required to file its own rating plans with the state's regulatory authority, Bamboo’s commissions are derived from a percentage of the premium rates set by its fronting carrier partners in conjunction with state law, and the sustainability of Bamboo’s business is dependent on such rates.
While Distinguished is not an insurer, and thus not required to file its own rating plans with the state's regulatory authority, Distinguished’s commissions are derived from a percentage of the premium rates set by its insurance carrier partners in conjunction with state law, and the sustainability of Distinguished’s business is dependent on such rates.
As of December 31, 2023, White Mountains reported $107 million of total assets, $67 million of total equity (net of intercompany eliminations) and $9 million of noncontrolling interests related to these businesses. White Mountains also has noncontrolling equity interests in various other operating businesses, which are generally accounted for at fair value within other long-term investments.
As of December 31, 2024, White Mountains reported $100 million of total assets, $65 million of total equity (net of intercompany eliminations) and $9 million of noncontrolling interests related to these businesses. White Mountains also has noncontrolling equity interests in various other operating businesses, which are generally accounted for at fair value within other long-term investments.
No payment of principal or interest on the BAM Surplus Notes may be made without the approval of the NYDFS. During 2024, HG Global received cash payments of principal and interest on the BAM Surplus Notes totaling $30 million.
No payment of principal or interest on the BAM Surplus Notes may be made without the approval of the NYDFS. During 2025, HG Global received cash payments of principal and interest on the BAM Surplus Notes totaling $35 million.
White Mountains has established relationships with select third-party registered investment advisers to manage a portion of its fixed income portfolio. See “ Portfolio Composition ” on page 71 . White Mountains maintains an equity portfolio that consists of common equity securities, its investment in MediaAlpha and other long-term investments.
White Mountains has established relationships with select third-party registered investment advisers to manage a portion of its fixed income portfolio. White Mountains maintains an equity portfolio that consists of common equity securities, its investment in MediaAlpha and other long-term investments.
During the years ended December 31, 2024, 2023 and 2022, Ark received a significant portion of its gross written premiums from four insurance and reinsurance intermediaries.
During the years ended December 31, 2025, 2024 and 2023, Ark received a significant portion of its gross written premiums from five insurance and reinsurance intermediaries.
Ark competes with insurance and reinsurance companies who operate in the Bermuda and Lloyd’s markets such as: • Bermuda insurance and reinsurance market: American International Group, Inc., Arch Capital Group Ltd., Aspen Insurance Holdings Ltd., AXIS Capital Holdings Ltd., Chubb Ltd., Everest Re Group, Markel Group, Inc., RenaissanceRe Holdings Ltd., SiriusPoint Ltd. and others; • Lloyd’s market: Beazley plc, Hiscox plc, Lancashire Holdings Ltd., MS Amlin Ltd. and other syndicates.
Ark competes with insurance and reinsurance companies who operate in the Bermuda and Lloyd’s markets such as: • Bermuda insurance and reinsurance market: American International Group, Inc., Arch Capital Group Ltd., Ascot Group Ltd., Aspen Insurance Holdings Ltd., Chubb Ltd., Everest Re Group, Markel Group, Inc., RenaissanceRe Holdings Ltd., Sompo Holdings Inc., SiriusPoint Ltd. and others; • Lloyd’s market: AXIS Capital Holdings Ltd., Beazley plc, Canopius Group Ltd., Convex Group Ltd., Hiscox plc, Lancashire Holdings Ltd., QBE Insurance Group Ltd. and other syndicates.
The following table presents Ark’s gross written premiums by line of business for the years ended December 31, 2024, 2023 and 2022: Year Ended December 31, Millions 2024 2023 2022 Property $ 1,080.8 $ 917.0 $ 605.0 Specialty 450.0 436.6 380.1 Marine & Energy 449.6 375.7 315.1 Casualty 130.6 98.7 85.4 Accident & Health 96.0 70.4 66.4 Total gross written premiums $ 2,207.0 $ 1,898.4 $ 1,452.0 4 A description of Ark’s business written within each line of business follows: Property Ark’s property business is underwritten on both an insurance and reinsurance basis covering the financial consequences of accidental losses to an insured’s property, such as a business’s building, inventory and equipment, or personal property.
The following table presents Ark’s gross written premiums by line of business for the years ended December 31, 2025, 2024 and 2023: Year Ended December 31, Millions 2025 2024 2023 Property $ 1,178.0 $ 1,080.8 $ 917.0 Specialty 646.7 450.0 436.6 Marine & Energy 453.6 449.6 375.7 Casualty 168.8 130.6 98.7 Accident & Health 110.1 96.0 70.4 Total gross written premiums $ 2,557.2 $ 2,207.0 $ 1,898.4 4 A description of Ark’s business written within each line of business follows: Property Ark’s property business is underwritten on both an insurance and reinsurance basis covering the financial consequences of accidental losses to an insured’s property, such as a business’s building, inventory and equipment, or personal property.
As of December 31, 2024 and 2023, the Collateral Trusts held total assets of $950 million and $949 million. 12 BAM Surplus Notes Through June 30, 2024, the interest rate on the BAM Surplus Notes was a variable rate equal to the one-year U.S.
As of December 31, 2025 and 2024, the Collateral Trusts held total assets of $1,007 million and $950 million. BAM Surplus Notes Through June 30, 2024, the interest rate on the BAM Surplus Notes was a variable rate equal to the one-year U.S.
As of December 31, 2024, BAM had assigned two credits to surveillance category 3 and did not assign any credits to surveillance category 4. Insured municipal bonds on the watchlist are monitored closely and are subject to BAM’s distressed credit management procedures, including a remediation plan developed in consultation with BAM’s legal counsel and consultants and HG Re.
As of December 31, 2025, BAM had assigned one credit to surveillance category 3. BAM has not assigned any credits to surveillance category 4 since inception. Insured municipal bonds on the watchlist are monitored closely and are subject to BAM’s distressed credit management procedures, including a remediation plan developed in consultation with BAM’s legal counsel and consultants and HG Re.
The following tables present HG Re’s ten largest exposures based upon the par value of policies assumed as of December 31, 2024 and 2023: December 31, 2024 $ in Millions Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Credit Rating (1) Metropolitan Transportation Authority (MTA), NY, Mass Transit - Farebox $ 79.7 0.4 % A- Midway Airport, City of Chicago, IL (Cook County), Airport GARBs (2023 Supplemental Indenture) 77.0 0.4 A City of Sherman, TX, (Grayson County), Combined Water & Sewer 76.4 0.4 A South Carolina Public Service Authority 73.1 0.4 A- City of Chicago, IL (Cook County), Sales Tax - Local 71.6 0.4 AA- New Jersey Transportation Trust Fund Authority, System & Program Bonds, NJ, Gas Tax - State 69.2 0.4 A- Pennsylvania Turnpike Commission, PA, Toll Roads 64.8 0.4 A+ Port Authority of NY and NJ 63.0 0.3 AA- State of Illinois, General Obligation Bonds 61.9 0.3 A- City of Wichita, KS (Sedgwick County), Water & Sewer 61.6 0.3 AA- Total of top ten exposures $ 698.3 3.7 % (1) The credit ratings are based on Standard & Poor’s credit ratings, or if unrated by Standard & Poor’s, the Standard & Poor’s equivalent of credit ratings provided by Moody’s.
“AA+” is the second highest, “A+” is the fifth highest, “A” is the sixth highest, “A-” is the seventh highest and “BBB” is the ninth highest of 23 credit ratings assigned by Standard & Poor’s. 14 December 31, 2024 $ in Millions Outstanding Par Value of Policies Assumed Percent of Total Outstanding Par Value of Policies Assumed Credit Rating (1) Metropolitan Transportation Authority (MTA), NY, Mass Transit - Farebox $ 79.7 0.4 % A- Midway Airport, City of Chicago, IL (Cook County), Airport GARB (2023 Supplemental Indenture) 77.0 0.4 A City of Sherman, TX, (Grayson County), Combined Water & Sewer 76.4 0.4 A South Carolina Public Service Authority 73.1 0.4 A- City of Chicago, IL (Cook County), Sales Tax - Local 71.6 0.4 AA- New Jersey Transportation Trust Fund Authority, System & Program Bonds, NJ, Gas Tax - State 69.2 0.4 A- Pennsylvania Turnpike Commission, PA, Toll Roads 64.8 0.4 A+ Port Authority of NY and NJ 63.0 0.3 AA- State of Illinois, General Obligation Bonds 61.9 0.3 A- City of Wichita, KS (Sedgwick County), Water & Sewer 61.6 0.3 AA- Total of top ten exposures $ 698.3 3.7 % (1) The credit ratings are based on Standard & Poor’s credit ratings, or if unrated by Standard & Poor’s, the Standard & Poor’s equivalent of credit ratings provided by Moody’s.
The Supplemental Trust balance as of December 31, 2024 and 2023 was $598 million and $607 million, which included $289 million and $247 million of cash, investments and accrued investment income, $301 million and $322 million of BAM Surplus Notes at nominal value and $8 million and $38 million of accrued interest receivable on the BAM Surplus Notes at nominal value.
The Supplemental Trust balance as of December 31, 2025 and 2024 was $607 million and $598 million, which included $323 million and $289 million of cash, investments and accrued investment income, $277 million and $301 million of BAM Surplus Notes at nominal value and $7 million and $8 million of accrued interest receivable on the BAM Surplus Notes at nominal value.
As of December 31, 2024 and 2023, the principal balance on the BAM Surplus Notes was $301 million and $322 million and total interest receivable on the BAM Surplus Notes was $195 million and $175 million, all at nominal value.
As of December 31, 2025 and 2024, the principal balance on the BAM Surplus Notes was $277 million and $301 million and total interest receivable on the BAM Surplus Notes was $214 million and $195 million, all at nominal value.
Reinsurance Treaties HG Global provides reinsurance exclusively to BAM. Through the reinsurance relationship with BAM, HG Global maintains a direct dialogue and line of sight into key operations, including the application of both BAM’s underwriting guidelines and the FLRT underwriting guidelines, continuous portfolio monitoring, credit surveillance and claims paying resources.
Through the reinsurance relationship with BAM, HG Global maintains a direct dialogue and line of sight into key operations, including the application of both BAM’s underwriting guidelines and the FLRT underwriting guidelines, continuous portfolio monitoring, credit surveillance and claims paying resources. HG Global reinsures all BAM policies that meet the FLRT underwriting guidelines.
Prior to the deconsolidation of BAM on July 1, 2024, HG Re’s reinsurance balances under the FLRT eliminated in White Mountains’s consolidated financial statements. Subsequent to the deconsolidation, White Mountains recognized gross written premiums of $32 million and earned premiums of $15 million during the year ended December 31, 2024.
For the year ended December 31, 2025, HG Re recognized gross written premiums of $61 million and earned premiums of $31 million. Prior to the deconsolidation of BAM on July 1, 2024, HG Re’s reinsurance balances under the FLRT eliminated in White Mountains’s consolidated financial statements.
While not currently material to our operations, Syndicates 4020 and 3902 also access insurance business from the European Economic Area though the London Branch of Lloyd’s Insurance Company. Lloyd’s Insurance Company is authorized and regulated by the National Bank of Belgium and regulated by the Financial Services and Markets Authority.
While not currently material to Ark’s operations, the Syndicates also access insurance business from the European Economic Area through the London Branch of Lloyd’s Insurance Company. Lloyd’s Insurance Company is authorized and regulated by the National Bank of Belgium and regulated by the Financial Services and Markets Authority. 27 U.K.
Reinsurance Protection As part of its enterprise risk management function, Ark purchases reinsurance for risk mitigation purposes. Ark utilizes reinsurance and retrocession agreements to reduce earnings volatility, protect capital, limit its exposure to risk concentration and accumulation of loss and manage within its overall internal risk tolerances or those set and agreed by regulators, ratings agencies and Lloyd’s.
Ark utilizes reinsurance and retrocession agreements to reduce earnings volatility, protect capital, limit its exposure to risk concentration and accumulation of loss and manage within its overall internal risk tolerances or those set and agreed by regulators, ratings agencies and Lloyd’s.
As of December 31, 2024 and 2023, White Mountains reported $1,108 million and $959 million of total assets and $792 million and $684 million of total equity related to Kudu.
As of December 31, 2025 and 2024, White Mountains reported $1,402 million and $1,108 million of total assets and $955 million and $792 million of total equity related to Kudu.
Gallagher & Co 12.5 16.9 12.5 Willis Towers Watson plc 4.9 5.0 9.4 Total proportion of business produced by the top four insurance and reinsurance intermediaries 56.6 % 66.1 % 66.1 % Underwriting and Pricing Ark aims to build a diversified and balanced portfolio of risks that generates an underwriting profit each year.
Gallagher & Co 15.2 12.5 16.9 Aon plc 12.4 13.4 16.7 Howden Insurance Group 8.7 6.4 4.6 Willis Towers Watson plc 4.1 4.9 5.0 Total proportion of business produced by the top five insurance and reinsurance intermediaries 64.7 % 63.0 % 70.7 % Underwriting and Pricing Ark aims to build a diversified and balanced portfolio of risks that generates an underwriting profit each year.
Lloyd’s approved stamp capacity in 2025 for Syndicate 4020, including ACSN 3832, is £750 million ($938 million based upon the foreign exchange spot rate as of December 31, 2024) and for Syndicate 3902 is £250 million ($313 million based upon the foreign exchange spot rate as of December 31, 2024).
Lloyd’s approved stamp capacity in 2026 for Syndicate 4020, including ACSN 3832, is £850 million ($1,148 million based upon the foreign currency exchange spot rate as of December 31, 2025) and for Syndicate 3902 is £250 million ($338 million based upon the foreign currency exchange spot rate as of December 31, 2025).
Ark also leads certain Lloyd’s market consortia, including two that target renewable energy clients including wind farms, solar plants, hydroelectric plants, geothermal plants and wave and tidal projects.
Ark also leads certain Lloyd’s market consortia, including two that target renewable energy clients including wind farms, solar plants, hydroelectric plants, geothermal plants and wave and tidal projects, as well as others that focus on property and power outage coverages.
Once the placement of Ark’s 2025 outwards reinsurance program is completed, Ark expects its net after-tax exposure for a 1-in-250 year event related to its largest PML zone to approximate 25-35% of total tangible capital (tangible shareholders equity and subordinated debt). Ark’s total tangible capital was $1,499 million as of December 31, 2024.
Once the placement of Ark’s 2026 outwards reinsurance program is completed, Ark expects its net after-tax peak exposure for a 1-in-250 year event related to its largest PML zone to approximate 20-35% of its tangible capital (tangible book value plus debt). Ark’s tangible capital was $1,833 million as of December 31, 2025.

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Item 1A. Risk Factors

Risk Factors — what could go wrong, per management

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Biggest changeShould its Capacity Providers reduce the volume of business accepted from Bamboo or adversely change the terms and conditions, we cannot guarantee that Bamboo would be able to find other Capacity Providers to write the business, which could materially adversely affect its results of operations and financial condition. 34 Bamboo primarily relies on third-party agents and brokers to distribute its products, and any deterioration in the relationships with these parties could adversely affect Bamboo’s business.
Biggest changeDistinguished primarily relies on third-party agents and brokers to distribute its products, and any deterioration in the relationships with these parties could adversely affect Distinguished’s business, which could materially adversely affect our results of operations and financial condition. Substantially all of Distinguished’s products are distributed through third-party agents and brokers who have the principal relationships with policyholders.
This could decrease the amount of bond insurance issued by BAM and thereby reduce payments on the Surplus Notes and risk premiums ceded to HG Re, both of which could materially adversely affect our results of operations and financial condition. 33 Risks Related to Kudu’s Business and Industry Kudu’s financial performance is dependent upon its clients’ asset and performance-based fees, which are subject to a variety of economic, market and other risks.
This could decrease the amount of bond insurance issued by BAM and thereby reduce payments on the BAM Surplus Notes and risk premiums ceded to HG Re, both of which could materially adversely affect our results of operations and financial condition. 33 Risks Related to Kudu’s Business and Industry Kudu’s financial performance is dependent upon its clients’ asset and performance-based fees, which are subject to a variety of economic, market and other risks.
The Pillar Two initiative includes a set of model rules that are generally designed to impose a top-up tax on a large multinational enterprise group to the extent the group is not subject to an effective tax rate of at least 15% in each jurisdiction in which the group has a consolidated affiliate or permanent establishment.
The Pillar Two initiative includes a set of model rules that are generally designed to impose a top-up tax on a large multinational enterprise group to the extent that the group is not subject to an effective tax rate of at least 15% in each jurisdiction in which the group has a consolidated affiliate or permanent establishment.
If any of our shareholders is a “U.S. 10% shareholder” (as described below) that directly or indirectly owns stock in White Mountains, that shareholder must include in its taxable income each year its pro rata share of our CFC subsidiaries’ “subpart F income” and global intangible low-taxed income for that year, even if no distributions are received by the U.S. 10% shareholder.
If any of our shareholders is a “U.S. 10% shareholder” (as described below) that directly or indirectly owns stock in White Mountains, that shareholder must include in its taxable income each year its pro rata share of our CFC subsidiaries’ “subpart F income” and global intangible low-taxed income (“GILTI”) for that year, even if no distributions are received by the U.S. 10% shareholder.
If you are a U.S. person, we encourage you to consult your own tax advisor concerning the potential tax consequences to you under the PFIC rules. 37 The Company and certain of our non-U.S. subsidiaries may become subject to U.S. tax, which could materially adversely affect our results of operations and financial condition.
If you are a U.S. person, we encourage you to consult your own tax advisor concerning the potential tax consequences to you under the PFIC rules. The Company and certain of our non-U.S. subsidiaries may become subject to U.S. tax, which could materially adversely affect our results of operations and financial condition.
The revenue that Kudu generates from its clients is subject to the same general economic and market risks that may affect our investment portfolio. See Risk Factors, “ Our investment portfolio may suffer reduced returns or losses, which could materially adversely affect our results of operations and financial condition.
Much of the revenue that Kudu generates from its clients is subject to the same general economic and market risks that may affect our investment portfolio. See Risk Factors, “ Our investment portfolio may suffer reduced returns or losses, which could materially adversely affect our results of operations and financial condition.
To qualify for the deferral, the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries, and (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets.
To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries and (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets.
As a result, the reinsurance business historically has been a cyclical industry characterized by periods of intense price competition due to excess underwriting capacity, as well as periods when shortages of capacity permitted improvements in reinsurance rate levels and terms and conditions.
As a result, the reinsurance industry historically has been cyclical, characterized by periods of intense price competition due to excess underwriting capacity, as well as periods when shortages of capacity permitted improvements in reinsurance rate levels and terms and conditions.
A downgrade, withdrawal or negative watch/outlook of these financial strength ratings also could limit Ark’s ability to raise new debt or could cause new and certain existing debt to be costlier and/or have more restrictive conditions. 30 Ark may not successfully alleviate risk through reinsurance and retrocessional arrangements, which could materially adversely affect our results of operations and financial condition.
A downgrade, withdrawal or negative watch/outlook of these financial strength ratings also could limit Ark’s ability to raise new debt or could cause new and certain existing debt to be costlier and/or have more restrictive conditions. 30 Ark may not adequately alleviate risk through reinsurance and retrocessional arrangements, which could materially adversely affect our results of operations and financial condition.
Because Bamboo primarily relies on third-party agents and brokers as its sales channel, any deterioration in the relationships with these parties or failure to provide competitive compensation could lead them to place less premium with Bamboo. Bamboo places a substantial portion of its premium through a limited number of agents and broker relationships.
Because Distinguished primarily relies on third-party agents and brokers as its sales channel, any deterioration in the relationships with these parties or failure to provide competitive compensation could lead them to place less premium with Distinguished. Distinguished places a substantial portion of its premium through a limited number of agents and broker relationships.
Kudu’s investees generate their revenues and earnings by charging asset-based fees, which are typically a percentage of the value of the assets they manage for their clients, and/or performance-based fees, which are typically a portion of actual returns achieved for their clients above a target return.
Kudu’s managers generate their revenues and earnings by charging asset-based fees, which are typically a percentage of the value of the assets they manage for their clients, and/or performance-based fees, which are typically a portion of actual returns achieved for their clients above a target return.
Ark competes with other Lloyd’s syndicates, London market participants and major U.S., Bermuda, European and other international insurance and reinsurance companies. Many of these competitors have greater resources than Ark does, have established long-term and continuing business relationships throughout the insurance and reinsurance industries and may have higher financial strength ratings, which can represent significant competitive advantages for them.
Ark competes with other Lloyd’s syndicates, London market participants and major U.S., Bermuda, European and other international insurance and reinsurance companies. Many of these competitors have greater financial resources, have more established long-term and continuing business relationships throughout the insurance and reinsurance industries and may have higher financial strength ratings, which can represent significant competitive advantages for them.
As a result, White Mountains’s reported book value per share and adjusted book value per share may be subject to future volatility, as the valuation of its investment in MediaAlpha is based on the publicly-traded share price of MediaAlpha’s common stock.
As a result, White Mountains’s reported book value per share may be subject to future volatility, as the valuation of its investment in MediaAlpha is based on the publicly-traded share price of MediaAlpha’s common stock.
For further discussion of our loss and LAE reserves, see “CRITICAL ACCOUNTING ESTIMATES — Loss and LAE Reserves” on page 85 . Risks Related to HG Global’s Business and Industry HG Re is only licensed to provide reinsurance to BAM.
For further discussion of our loss and LAE reserves, see “CRITICAL ACCOUNTING ESTIMATES — Loss and LAE Reserves” on page 90 . Risks Related to HG Global’s Business and Industry HG Re is only licensed to provide reinsurance to BAM.
These investments can experience volatility in their returns or valuation, which could materially adversely affect our results of operations and financial condition. 35 We may be subject to volatility from our investment in MediaAlpha, which could materially adversely affect our results of operations and financial condition.
These investments can experience volatility in their returns or valuations, which could materially adversely affect our results of operations and financial condition. 35 We may be subject to volatility from our investment in MediaAlpha, which could materially adversely affect our results of operations and financial condition.
See “BAM Surplus Notes” under “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 82 for a description of the methodology and key inputs we use to determine the valuation of the BAM Surplus Notes.
See “BAM Surplus Notes” under “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 88 for a description of the methodology and key inputs we use to determine the valuation of the BAM Surplus Notes.
See “ CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 82 for a description of the methodologies we use to determine the GAAP fair value of our investments without a readily observable market price.
See “ CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 87 for a description of the methodologies we use to determine the GAAP fair value of our investments without a readily observable market price.
Loss and LAE reserves are estimates of what Ark/WM Outrigger believes the settlement and administration of claims will cost based on facts and circumstances then known.
Loss and LAE reserves are estimates of what Ark believes the settlement and administration of claims will cost based on facts and circumstances then known.
These estimates involve actuarial and claims assessments and require Ark/WM Outrigger to make a number of assumptions about future events that are subject to unexpected changes and are beyond Ark/WM Outrigger’s control, such as future trends in claim severity, emerging coverage issues, frequency, inflation, legislative and judicial changes, regulatory changes, adverse court rulings and other factors.
These estimates involve actuarial and claims assessments and require Ark to make a number of assumptions about future events that are subject to unexpected changes and are beyond Ark’s control, such as future trends in claim severity, emerging coverage issues, frequency, inflation, legislative and judicial changes, regulatory changes, adverse court rulings and other factors.
In addition, a data breach could subject us to legal liability or regulatory action under data protection and privacy laws and regulations enacted by federal, state and foreign governments or other regulatory bodies. As a result, our ability to conduct our business and our results of operations and financial condition could be materially adversely affected.
In addition, a data breach could subject us to legal liability or regulatory action under data protection and privacy laws and regulations enacted by federal, state and foreign governments or other regulatory bodies. As a result, our ability to conduct our business could be adversely impacted, which could materially adversely affect our results of operations and financial condition.
Accordingly, if the assumptions are incorrect, the losses Ark and WM Outrigger Re might incur from an actual catastrophe could be materially different than the expectation of losses generated from modeled catastrophe scenarios, which could materially adversely affect our results of operations and financial condition. Ark and its subsidiaries benefit from favorable financial strength ratings from A.M.
Accordingly, if the assumptions are incorrect, the actual losses Ark might incur from a catastrophe could be materially different than the expectation of losses generated from modeled catastrophe scenarios, which could materially adversely affect our results of operations and financial condition. Ark and its subsidiaries benefit from favorable financial strength ratings from A.M.
It is unlikely that BAM would pay principal and interest on the BAM Surplus Notes if such payments could lead to a rating downgrade. In 2024, the NYDFS approved cash payments of principal and interest on the BAM Surplus Notes totaling $30 million. We cannot guarantee that the NYDFS will approve payments on the BAM Surplus Notes in the future.
It is unlikely that BAM would pay principal and interest on the BAM Surplus Notes if such payments could lead to a rating downgrade. In 2025, the NYDFS approved cash payments of principal and interest on the BAM Surplus Notes totaling $35 million. We cannot guarantee that the NYDFS will approve payments on the BAM Surplus Notes in the future.
If Ark is unable to maintain its competitive position throughout soft and hard market cycles, its business may be adversely affected, and it may not be able to compete effectively in the future, which could materially adversely affect our results of operations and financial condition. 31 Ark/WM Outrigger’s loss and LAE reserves may be inadequate to cover the ultimate liability for losses, and as a result, our results of operations and financial condition could be adversely affected.
If Ark is unable to maintain its competitive position throughout soft and hard market cycles, its business may be adversely affected, and it may not be able to compete effectively in the future, which could materially adversely affect our results of operations and financial condition. 31 Ark’s loss and LAE reserves may be inadequate to cover the ultimate liability for losses, which could materially adversely affect our results of operations and financial condition.
However, a person that is a U.S. 10% shareholder solely as a result of constructive ownership rules (i.e., such person does not directly or indirectly own stock of White Mountains) should not have a subpart F income inclusion or global intangible low-taxed income with respect to our CFC subsidiaries.
However, a person that is a U.S. 10% shareholder solely as a result of constructive ownership rules (i.e., such person does not directly or indirectly own stock of White Mountains) should not have a subpart F income inclusion or GILTI inclusion with respect to our CFC subsidiaries.
On December 27, 2023, Bermuda enacted a 15% corporate income tax that became effective on January 1, 2025. The Bermuda legislation defers the effective date until January 1, 2030, for Bermuda companies in consolidated groups that meet certain requirements.
On December 27, 2023, Bermuda enacted a 15% corporate income tax that became effective on January 1, 2025. The Bermuda legislation defers the effective date for five years for Bermuda companies in consolidated groups that meet certain requirements.
During the time that BAM’s financial strength rating was placed on credit watch negative by Standard & Poor’s, it voluntarily withdrew from the marketplace and did not write any municipal bond insurance policies. On May 29, 2024, Standard & Poor’s concluded its most recent review and affirmed BAM’s “AA/stable” financial strength rating.
During the time that BAM’s financial strength rating was placed on credit watch negative by Standard & Poor’s, it voluntarily withdrew from the marketplace and did not write any municipal bond insurance policies. On July 11, 2025, Standard & Poor’s concluded its most recent review and affirmed BAM’s “AA/stable” financial strength rating.
Ark/WM Outrigger must maintain reserves adequate to cover its estimated ultimate liabilities for loss and LAE. Loss and LAE reserves are typically comprised of (i) case reserves for reported claims and (ii) incurred but not reported (“IBNR”) reserves for losses that have occurred but for which claims have not yet been reported and for expected future development on case reserves.
Ark maintains reserves to cover its estimated ultimate liabilities for loss and LAE. Loss and LAE reserves are typically comprised of (i) case reserves for reported claims and (ii) incurred but not reported (“IBNR”) reserves for losses that have occurred but for which claims have not yet been reported and for expected future development on case reserves.
Additionally, Kudu’s investees participate in a highly competitive, highly regulated industry that subjects their operations to a number of other risks that are out of our control and could materially adversely affect our results of operations and financial condition, including (i) changes in investor preference from the actively-managed investments offered by Kudu’s investees to passively-managed investments; (ii) the ability of Kudu’s investees to successfully attract new clients and retain existing ones; (iii) the ability of Kudu’s investees to avoid fee compression; (iv) the reliance of Kudu’s investees on a small number of key personnel; and (v) future changes to regulations that make Kudu’s investees’ businesses more cumbersome and expensive to operate.
Additionally, Kudu’s managers participate in a highly competitive, highly regulated industry that subjects their operations to a number of other risks that are out of our control, including (i) changes in investor preference from the actively-managed investments offered by Kudu’s managers to passively-managed investments; (ii) the ability of Kudu’s managers to successfully attract new clients and retain existing ones; (iii) the ability of Kudu’s managers to avoid fee compression; (iv) the reliance of Kudu’s managers on a small number of key personnel; and (v) future changes to regulations that make Kudu’s managers’ businesses more cumbersome and expensive to operate.
As of December 31, 2024, White Mountains owned $1,263 million in securities, including our investments in Kudu’s Participation Contracts and PassportCard/DavidShield, that are not actively traded in public markets, do not have readily observable market prices and are classified as Level 3 investments in the GAAP fair value hierarchy.
As of December 31, 2025, White Mountains owned $1,814 million in securities, including Kudu’s Participation Contracts, the Bamboo SPV and PassportCard/DavidShield, that are not actively traded in public markets, do not have readily observable market prices and are classified as Level 3 investments in the GAAP fair value hierarchy.
As a result, such actions could have a material adverse effect on our results of operations and financial condition. 39 Bermuda law differs from the laws in effect in the United States and may afford less protection to shareholders. We are organized under the laws of Bermuda, and a portion of our assets are located outside the United States.
As a result, such actions could materially adversely affect our results of operations and financial condition. 39 Bermuda law differs from the laws in effect in the United States and may afford less protection to shareholders. We are organized under the laws of Bermuda, and a significant portion of our assets are located outside the United States.
Ark and WM Outrigger Re write insurance and reinsurance policies that cover unpredictable catastrophic events all over the world. Ark and WM Outrigger Re have exposure to losses caused by events including natural and other disasters such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis and severe weather.
Ark underwrites insurance and reinsurance policies that cover unpredictable catastrophic events all over the world. Ark has exposure to losses caused by natural disasters and other events such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis and severe weather.
Inability to collect amounts due from reinsurers, including Outrigger Re Ltd., can result from a number of scenarios, including: (i) reinsurers choosing to withhold payment due to a dispute or other factors beyond Ark’s control; (ii) reinsurers becoming unable to pay amounts owed to Ark as a result of a deterioration in their financial condition; and (iii) losses exceeding amounts within the collateral trust accounts for Outrigger Re Ltd.
The inability to collect amounts due from reinsurers, including Outrigger Re Ltd., can result from a number of scenarios, including: (i) reinsurers withholding payment due to a dispute, including coverage terms, adverse judicial rulings or failed arbitration, or other factors beyond Ark’s control; (ii) reinsurers becoming unable to pay amounts owed to Ark as a result of a deterioration in their financial condition; and (iii) in the case of Outrigger Re Ltd., losses exceeding amounts within the collateral trust accounts.
An impairment of goodwill or other intangible assets occurs when the carrying value of the asset exceeds its fair value. The evaluation of goodwill or other intangible assets for impairment requires the use of significant judgment in determining fair value, including assumptions about the future performance of the associated business.
The evaluation of goodwill or other intangible assets for impairment requires the use of significant judgment in determining fair value, including assumptions about the future performance of the associated business.
The EU Minimum Tax Directive also permits European Union Member States to elect to apply a Qualified Domestic Minimum Top-up Tax (“QDMTT”) for fiscal years beginning on or after December 31, 2023. On December 20, 2023, Luxemburg enacted conforming Pillar Two legislation.
The EU Minimum Tax Directive also permits European Union Member States to elect to apply a Qualified Domestic Minimum Top-up Tax (“QDMTT”) for fiscal years beginning on or after December 31, 2023. On July 11, 2023, the United Kingdom enacted conforming Pillar Two legislation including the IIR and QDMTT.
White Mountains’s investment in MediaAlpha is valued based on the publicly-traded share price of MediaAlpha’s common stock, which at the December 31, 2024 closing price of $11.29 per share was $202 million.
White Mountains’s investment in MediaAlpha is valued based on the publicly-traded share price of MediaAlpha’s common stock, which at the December 31, 2025 closing price of $12.95 per share was $231 million.
As of December 31, 2024, White Mountains owned BAM Surplus Notes with a principal balance of $301 million and accrued interest receivable of $195 million, both at nominal value. The BAM Surplus Notes were carried at their fair value of $382 million as of December 31, 2024.
As of December 31, 2025, White Mountains owned BAM Surplus Notes with a principal balance of $277 million and accrued interest receivable of $214 million, both at nominal value. The BAM Surplus Notes were carried at a fair value of $339 million as of December 31, 2025.
The municipal bond industry is highly regulated at the federal and state level, and certain municipal bonds enjoy preferential tax treatment. Significant changes to these regulations or to the tax treatment of municipal bonds could affect the attractiveness of and market for BAM’s financial guarantee solutions.
The municipal bond market is subject to regulations at both the federal and state level, and certain municipal bonds enjoy preferential tax treatment. Changes to such regulations or to the tax treatment of municipal bonds could affect the issuance of certain municipal bonds or could reduce the attractiveness of and market for BAM’s financial guarantee solutions.
If BAM does not repay some or all of the principal and interest on the BAM Surplus Notes, it could materially adversely affect our results of operations and financial condition.
If BAM does not repay some or all of the principal and interest on the BAM Surplus Notes, it could materially adversely affect our results of operations and financial condition. We may be subject to volatility from the valuation of the BAM Surplus Notes, which could materially adversely affect our results of operations and financial condition.
Best and “AA-/stable” by Standard & Poor’s assigned to the Lloyd’s marketplace. Beginning in January 2021, Ark began writing certain classes of its business through GAIL, Ark’s wholly-owned Bermuda-based insurance and reinsurance company, which has an “A/stable” financial strength rating by A.M. Best. See “ RATINGS ” on page 28 .
Best and “AA-/stable” by Standard & Poor’s assigned to the Lloyd’s marketplace. GAIL, Ark’s wholly-owned Bermuda-based insurance and reinsurance company, has an “A/stable” financial strength rating by A.M. Best. See “ RATINGS ” on page 28 .
Should Bamboo fail to meet the profitability expectations of its Capacity Providers that write the business it places, its Capacity Providers could choose to stop writing the business or reduce the commission rate they will pay for placement services, which could materially adversely affect our results of operations and financial condition.
Should Distinguished fail to meet the profitability expectations of the carriers that underwrite the business it places, those carriers could choose to stop underwriting the business or reduce the commission rate they will pay for placement services, which could materially adversely affect Distinguished’s commission revenues and, consequently, could materially adversely affect our results of operations and financial condition.
Bamboo is an MGA and program administrator with delegated binding authorities, and as such, is generally dependent on its Capacity Providers to bear the insurance risk on the programs designed and underwritten by Bamboo.
Distinguished is an MGA and program administrator with delegated binding authorities, and as such, its carrier partners bear the insurance risk on the programs designed and underwritten by Distinguished.
This could in turn materially adversely affect HG Re’s business and, consequently, could materially adversely affect our results of operations and financial condition. The municipal bond market is subject to regulations at both the federal and state level, and certain municipal bonds enjoy preferential tax treatment.
The municipal bond industry is highly regulated at the federal and state level, and certain municipal bonds enjoy preferential tax treatment. Significant changes to these regulations or to the tax treatment of municipal bonds could materially adversely affect BAM’s and HG Re’s business and, consequently, could materially adversely affect our results of operations and financial condition.
Should this fronting partner reduce the volume of business accepted from Bamboo or adversely change the terms and conditions of placement, we cannot guarantee that Bamboo would be able to find other fronting partners to write its full programs, which could materially adversely affect its results of operations and financial condition.
Should any of these carriers reduce the volume of business accepted from Distinguished or adversely change the terms and conditions of placement, we cannot guarantee that Distinguished would be able to find other carriers to assume the business, which could materially adversely affect our results of operations and financial condition.
The Luxembourg legislation defers the effective date of the UTPR until fiscal years beginning after December 31, 2029 for Luxembourg companies in consolidated groups with a non-EU parent company that meet certain requirements.
The Luxembourg legislation defers the effective date of the UTPR for five years to fiscal years beginning on or after December 31, 2029 for Luxembourg companies in consolidated groups that meet certain requirements.
Such determinations have the effect of increasing Ark’s financial exposure to losses associated with risks that it underwrites and, in the event of significant losses associated with a given risk, could materially adversely affect our results of operations and financial condition.
Such a determination has the effect of increasing Ark’s financial exposure to losses associated with risks that it underwrites and, in the event of significant losses associated with a given risk, could materially adversely affect our results of operations and financial condition. Purchasing reinsurance does not relieve Ark of its underlying obligations to policyholders or ceding companies.
White Mountains expects to meet the requirements to be exempt from the Luxembourg UTPR until January 1, 2030. On July 11, 2023, the U.K. enacted conforming legislation adopting the Pillar Two IIR and QDMTT, which became effective for fiscal years beginning on or after December 31, 2023.
White Mountains expects to meet the requirements to be exempt from the U.K. UTPR until January 1, 2030. On December 20, 2023, Luxemburg enacted conforming Pillar Two legislation including the IIR, UTPR and QDMTT.
Claims from catastrophic events could materially adversely affect our results of operations and financial condition. Ark’s ability to write new insurance and reinsurance policies could also be impacted as a result of corresponding reductions in its capital levels.
Claims from catastrophic events could materially adversely affect our results of operations and financial condition. In addition, following a large loss event, Ark could have diminished capacity to write new insurance and reinsurance policies due to reductions in its capital levels.
As a result, Ark may not be able to successfully alleviate risk through these arrangements, which could materially adversely affect our results of operations and financial condition. In addition, due to factors such as the price or availability of reinsurance or retrocessional coverage, Ark sometimes decides to increase the amount of risk retained by purchasing less reinsurance.
In addition, the coverage provided by Ark’s reinsurance and retrocessional arrangements may not cover certain of its future liabilities. As a result, Ark may not be able to adequately alleviate risk through these arrangements, which could materially adversely affect our results of operations and financial condition.
White Mountains’s reported book value per share and adjusted book value per share may be subject to greater volatility in the future, as the valuation of the BAM Surplus Notes under the discounted cash flow analysis could be more volatile. We use judgment in selecting the key inputs to the discounted cash flow analysis.
As of December 31, 2025, the fair value of the BAM Surplus Notes was $339 million using a discounted cash flow analysis. White Mountains’s reported book value per share may be subject to volatility in the future, as the valuation of the BAM Surplus Notes under the discounted cash flow analysis could be volatile.
If you are a U.S. person who might be a U.S. 10% shareholder, we encourage you to consult your own tax advisor concerning the CFC rules.
The enacted provisions apply to tax years of foreign corporations beginning after December 31, 2025. If you are a U.S. person who might be a U.S. 10% shareholder or a FCUS shareholder, we encourage you to consult your own tax advisor concerning these rules.
A significant increase in interest rates that causes severe losses could materially adversely affect our results of operations and financial condition.
A significant increase in interest rates that causes severe losses could materially adversely affect our results of operations and financial condition. In addition, certain of our other long-term investments are not regularly traded in active investment markets and may be illiquid.
Additionally, the base erosion and profit shifting (“BEPS”) project currently being undertaken by the OECD and the European Commission’s investigation into illegal state aid may result in changes to long standing tax principles, which could materially adversely affect our results of operations and financial condition.
Additionally, the base erosion and profit shifting (“BEPS”) project currently being undertaken by the OECD and the European Commission’s investigation into illegal state aid may result in changes to long standing tax principles. The Bermuda corporate income tax and the Pillar Two worldwide minimum tax currently being enacted around the world are examples of the effects of the BEPS project.
We may be treated as a PFIC, in which case a U.S. holder of our common shares could be subject to disadvantageous rules under U.S. federal income tax laws. Significant potential adverse U.S. federal income tax consequences apply to any U.S. person who owns shares in a passive foreign investment company (“PFIC”).
Significant potential adverse U.S. federal income tax consequences apply to any U.S. person who owns shares in a passive foreign investment company (“PFIC”).
If we are required to write down goodwill and other intangible assets, it could materially adversely affect our results of operations and financial condition.
If we are required to write down goodwill and other intangible assets, it could materially adversely affect our results of operations and financial condition. As of December 31, 2025, we had total goodwill and other intangible assets of $1,020 million on our consolidated balance sheet, of which $578 million relates to Distinguished and $293 million relates to Ark.
Ark attempts to limit its risk of loss through reinsurance and retrocessional arrangements, including through its quota share reinsurance agreement with Outrigger Re Ltd. Retrocessional arrangements refer to reinsurance purchased by a reinsurer to cover its own risks assumed from ceding companies.
Ark attempts to limit its risk of loss through reinsurance and retrocessional arrangements. Retrocessional arrangements refer to reinsurance purchased by a reinsurer to cover its own risks assumed from ceding companies. The availability and cost of reinsurance and retrocessional protection is subject to market conditions, which are outside of Ark’s control.
Purchasing reinsurance does not relieve Ark of its underlying obligations to policyholders or ceding companies, so any inability to collect amounts due from reinsurers could materially adversely affect our results of operations and financial condition.
As a result, any inability to collect amounts due from reinsurers could materially adversely affect our results of operations and financial condition.
If the Bermuda government repeals or otherwise limits the economic transition adjustment, or if Luxembourg or the U.K. enacts the January 2025 OECD Administrative Guidance into its domestic Pillar Two law, our results of operations and financial condition may be materially adversely affected. 38 Our non-U.S. subsidiaries are treated as CFCs and may subject a U.S. 10% shareholder of our common shares to disadvantageous rules under U.S. federal income tax laws.
Such changes in tax laws or tax treaties could materially adversely affect our results of operations and financial condition. 38 Our non-U.S. subsidiaries are treated as CFCs and may subject a U.S. 10% shareholder of our common shares to disadvantageous rules under U.S. federal income tax laws.
In the event that Ark/WM Outrigger’s reserves are insufficient to cover the actual loss and LAE, Ark/WM Outrigger may need to add to the reserves, which could have a material adverse effect on our results of operations and financial condition.
Because of uncertainties associated with estimating ultimate loss and LAE reserves, we cannot be certain that Ark’s reserves are adequate. In the event that Ark’s reserves are insufficient to cover the actual loss and LAE, Ark may need to add to the reserves, which could materially adversely affect our results of operations and financial condition.
If White Mountains fails to meet the requirements of the five-year deferral under the Bermuda corporate income tax or the OECD Pillar Two UTPR, its results of operations and financial condition could be materially adversely affected.
The failure by White Mountains to meet the requirements of the five-year deferral under the Bermuda corporate income tax or the OECD Pillar Two UTPR could materially adversely affect our results of operations and financial condition. 37 We may be treated as a PFIC, in which case a U.S. holder of our common shares could be subject to disadvantageous rules under U.S. federal income tax laws.
Adverse changes in equity markets, interest rates, debt markets or foreign currency exchange rates could result in significant losses to the value of our investment portfolio. Our investment portfolio primarily consists of fixed maturity investments, short-term investments, common equity securities, our investment in MediaAlpha and other long-term investments.
Risks Related to Investments Our investment portfolio may suffer reduced returns or losses, which could materially adversely affect our results of operations and financial condition. Adverse changes in equity markets, interest rates, debt markets or foreign currency exchange rates could result in significant losses to the value of our investment portfolio.
Substantially all of Bamboo’s products are distributed through third-party agents and brokers who have the principal relationships with policyholders. Agents and brokers generally own the “renewal rights,” and thus Bamboo’s business model is dependent on its relationships with, and the success of, the agents and brokers with whom Bamboo does business.
Agents and brokers have significant influence over renewals, and thus Distinguished’s business model is dependent on its relationships with, and the success of, the agents and brokers with whom Distinguished does business.
For the year ended December 31, 2024, Bamboo placed substantially all of its business with one fronting partner.
Distinguished placed approximately 61% of its business with its three largest carriers during the year ended December 31, 2025.
Even if available, that reinsurance may not be available from entities with satisfactory creditworthiness. If Bamboo is unable to obtain satisfactory reinsurance, it would have to reduce the level of its underwriting commitments, which could materially adversely affect its results of operations and financial condition.
If Kudu’s managers are unable to compete effectively in the future, Kudu’s business may be materially adversely affected, which could materially adversely affect our results of operations and financial condition.
Removed
As of December 31, 2024, we had total goodwill and other intangible assets of $720 million on our consolidated balance sheet, $355 million of which relates to our acquisition of Bamboo and $293 million of which relates to our acquisition of Ark. We periodically review goodwill and other intangible assets to determine whether an impairment has occurred.
Added
We periodically review goodwill and other intangible assets to determine whether an impairment has occurred. An impairment of goodwill or other intangible assets occurs when the carrying value of the asset exceeds its fair value.
Removed
WM Outrigger Re’s obligations under its quota share reinsurance agreement with GAIL is subject to an aggregate limit equal to the assets in the collateral trust account at any point in time.
Added
In addition, due to various factors, including the price or availability of reinsurance or retrocessional coverage, Ark may decide to increase the amount of risk retained by purchasing less reinsurance.
Removed
The availability and cost of reinsurance and retrocessional protection is subject to market conditions, which are outside of Ark’s control. In addition, the coverage provided by Ark’s reinsurance and retrocessional arrangements may be inadequate to cover its future liabilities.
Added
For example, in 2025 White Mountains recognized a decrease of $38 million in the fair value of the BAM Surplus Notes. We use judgment in selecting the key inputs to the discounted cash flow analysis. With a discounted cash flow analysis, small changes to key inputs may result in significant changes to fair value.
Removed
Because of uncertainties associated with estimating ultimate loss and LAE reserves, we cannot be certain that Ark/WM Outrigger’s reserves are adequate.
Added
Additionally, Kudu’s managers participate in a highly competitive, highly regulated industry. Kudu’s managers may not be able to compete effectively in the future, which could materially adversely affect our results of operations and financial condition. Kudu provides capital solutions for asset and wealth management firms through Participation Contracts.
Removed
We may be subject to greater volatility from the BAM Surplus Notes, as the valuation of the BAM Surplus Notes under the discounted cash flow analysis subsequent to deconsolidation could be more volatile, which could materially adversely affect our results of operations and financial condition.
Added
Risks Related to Distinguished’s Business and Industry Distinguished’s commission revenues are dependent on many factors, some of which are beyond its control, including the pricing and profitability of certain segments of the property and casualty insurance industry, which is highly competitive and cyclical.
Removed
Under GAAP, for periods prior to July 1, 2024, the BAM Surplus Notes, including accrued interest receivable, were classified as intercompany notes carried at nominal value with no consideration for time value of money and eliminated in consolidation.
Added
Distinguished may not be able to compete effectively in the future, which could materially adversely affect our results of operations and financial condition. Distinguished generates most of its revenues from commissions that are a portion of premiums charged by insurance companies to their insureds.
Removed
Upon the deconsolidation of BAM on July 1, 2024, White Mountains elected the fair value option, and the BAM Surplus Notes, including accrued interest receivable, were fair valued at $387 million using a discounted cash flow analysis, which resulted in an unrealized loss on deconsolidation of $115 million.
Added
Distinguished’s future commission revenues could also be materially adversely affected by other factors beyond its control, including (i) the increasing availability of capital markets-based products designed to replace traditional insurance and reinsurance products; (ii) growth in the direct-to-consumer sales channel at the expense of insurance intermediaries including agents and brokers; (iii) the percentage of premium insurance carriers will pay for placement services; (iv) the availability and cost of reinsurance; and (v) future trends in claim severity, emerging coverage issues, frequency, inflation, legislative and judicial changes, regulatory changes, adverse court rulings and other factors.
Removed
This fair value includes the impact of a discount for the time value of money, which was previously included in adjusted book value per share as a non-GAAP adjustment to book value per share. As of December 31, 2024, the fair value of the BAM Surplus Notes was $382 million.
Added
The property and casualty insurance industry is highly competitive and has historically been cyclical, experiencing periods of severe price competition and less selective underwriting standards (soft markets) followed by periods of relatively high prices and more selective underwriting standards (hard markets).
Removed
Changes to such regulations or to the tax treatment of municipal bonds could affect the issuance of certain municipal bonds or could reduce the attractiveness of and market for BAM’s financial guarantee solutions.

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Item 2. Properties

Properties — owned and leased real estate

2 edited+0 added−1 removed1 unchanged
Biggest changeIn addition, Ark maintains underwriting offices in London, England and Hamilton, Bermuda. Kudu’s and WTM Partners’s headquarters are located in New York, New York. Bamboo’s headquarters are located in Midvale, Utah. The various offices and facilities of the consolidated Other Operating Businesses are owned or leased.
Biggest changeIn addition, Ark maintains underwriting offices in London, England and Hamilton, Bermuda. Kudu’s, Distinguished’s and WTM Partners’s headquarters are located in New York, New York. The various offices and facilities of the consolidated Other Operating Businesses are owned or leased. Management considers its office facilities suitable and adequate for its current level of operations. 42 Item 3. Legal Proceedings None.
In addition, White Mountains maintains professional offices in Guilford, Connecticut, which houses its corporate finance and investment functions, and Boston, Massachusetts, which houses its corporate accounting, reporting and internal audit functions. All of the Company’s professional offices are leased. HG Global’s, WM Outrigger Re’s and Ark’s headquarters are located in Hamilton, Bermuda.
In addition, White Mountains maintains professional offices in Guilford, Connecticut, which houses its corporate finance and investment functions, and Boston, Massachusetts, which houses its corporate accounting, reporting and internal audit functions. All of the Company’s professional offices are leased. Ark’s, WM Outrigger Re’s and HG Global’s headquarters are located in Hamilton, Bermuda.
Removed
Management considers its office facilities suitable and adequate for its current level of operations. 42 Item 3. Legal Proceedings None.

Item 4. Mine Safety Disclosures

Mine Safety Disclosures — required of mining issuers

10 edited+1 added−0 removed2 unchanged
Biggest changeHildreth was appointed as Managing Director and Chief Accounting Officer of the Company in May 2021. Prior to that, she served as Managing Director and General Auditor of WM Capital. She joined White Mountains in 2003 and has served in a variety of accounting and auditing-related positions with the Company and its subsidiaries. Prior to joining the Company, Ms.
Biggest changePapamichael held various senior positions at Sirius Group, including when it was owned by White Mountains prior to 2016. Ms. Hildreth was appointed as Managing Director and Chief Accounting Officer of the Company in May 2021. Prior to that, she served as Managing Director and General Auditor of WM Capital.
Prior to joining Farmers, he was CEO of Regional Markets EMEA for Zurich Insurance Group, based in Zurich. Prior to this, he led the Zurich Group’s mergers, acquisitions and partnership activities globally. Prior to Zurich, Mr. Harrison was an investment banker at Lehman Brothers and HSBC. Mr. Harrison also serves as a director of BAM. Ms.
Prior to joining Farmers, he was CEO of Regional Markets EMEA for Zurich Insurance Group, based in Zurich. Prior to this, he led the Zurich Group’s mergers, acquisitions and partnership activities globally. Prior to Zurich, Mr. Harrison was an investment banker at Lehman Brothers and HSBC. Mr. Harrison also serves as a director of BAM. Mr.
In addition, the Company’s code of business conduct and ethics as well as the various charters governing the actions of certain of the Company’s Committees of its Board of Directors, including its Audit Committee and Compensation/Nominating & Governance Committee, are available at www.whitemountains.com .
In addition, the Company’s Code of Business Conduct as well as the various charters governing the actions of certain of the Company’s Committees of its Board of Directors, including its Audit Committee and Compensation/Nominating & Governance Committee, are available at www.whitemountains.com .
Harrison was appointed Executive Vice President and Chief Strategy Officer of the Company in June 2024. Prior to joining White Mountains, Mr. Harrison worked for the Zurich Insurance Group from 2015 to 2024, most recently as the Chief Financial Officer of Farmers Group, Inc.
Prior to that, he served as Executive Vice President and Chief Strategy Officer of the Company. Prior to joining White Mountains in June 2024, Mr. Harrison worked for the Zurich Insurance Group from 2015 to 2024, most recently as the Chief Financial Officer of Farmers Group, Inc.
Seelig Executive Vice President and General Counsel 56 2002 All executive officers of the Company and its subsidiaries are elected by the Board for a term of one year or until their successors have been elected and have duly qualified. Information with respect to the principal occupation and relevant business experience of the Executive Officers follows: Mr.
Seelig Executive Vice President and General Counsel 57 2002 All executive officers of the Company are elected by the Board for a term of one year or until their successors are duly elected and qualified. Information with respect to the principal occupation and relevant business experience of the Executive Officers follows: Mr.
INFORMATION ABOUT OUR EXECUTIVE OFFICERS (as of February 27, 2025) Name Position Age Executive Officer Since G. Manning Rountree Chief Executive Officer 52 2009 Liam P. Caffrey President and Chief Financial Officer 52 2022 Giles E. Harrison Executive Vice President and Chief Strategy Officer 56 2024 Michaela J. Hildreth Managing Director and Chief Accounting Officer 57 2021 Robert L.
INFORMATION ABOUT OUR EXECUTIVE OFFICERS (as of February 27, 2026) Name Position Age Executive Officer Since Liam P. Caffrey Chief Executive Officer 53 2022 Giles E. Harrison President 57 2024 Michael A. Papamichael Managing Director and Chief Financial Officer 45 2026 Michaela J. Hildreth Managing Director and Chief Accounting Officer 58 2021 Robert L.
Prior to joining White Mountains in March 2022, Mr. Caffrey served as Chief Executive Officer of Aon’s Global Affinity business. Prior to that, he served as Chief Financial Officer of Aon Risk Solutions globally and as Chief Financial Officer of Aon Risk Solutions Americas. Prior to joining Aon, Mr. Caffrey spent 12 years with McKinsey & Company. Mr.
Prior to that, he served as Chief Financial Officer of Aon Risk Solutions globally and as Chief Financial Officer of Aon Risk Solutions Americas. Prior to joining Aon, Mr. Caffrey spent 12 years with McKinsey & Company. Mr. Harrison was appointed as President in January 2026.
Hildreth spent 13 years with PricewaterhouseCoopers. Mr. Seelig is Executive Vice President and General Counsel of the Company. Prior to joining White Mountains in 2002, Mr. Seelig was with the law firm of Cravath, Swaine & Moore. 43 PART II
Prior to joining White Mountains in 2002, Mr. Seelig was with the law firm of Cravath, Swaine & Moore. 43 PART II
Rountree was a Senior Vice President at Putnam Investments for two years. Prior to joining Putnam Investments, Mr. Rountree spent three years with McKinsey & Company. Mr. Caffrey was appointed as President and Chief Financial Officer of the Company in April 2024. Prior to that, he served as Executive Vice President and Chief Financial Officer of the Company.
Caffrey was appointed as Chief Executive Officer in January 2026. Prior to that, he served as President and Chief Financial Officer of the Company since April 2024. Prior to that, he served as Executive Vice President and Chief Financial Officer. Prior to joining White Mountains in March 2022, Mr. Caffrey served as Chief Executive Officer of Aon’s Global Affinity business.
Rountree was appointed as a director and Chief Executive Officer of the Company in March 2017. Prior to that, he served as an Executive Vice President of the Company and President of WM Capital. He joined White Mountains in 2004 and served as President of WM Advisors from March 2009 until December 2014. Prior to joining White Mountains, Mr.
Papamichael was appointed as Managing Director and Chief Financial Officer in January 2026. Prior to that, he served as Managing Director and Deputy Chief Financial Officer. Prior to joining White Mountains in 2020, Mr. Papamichael served as a Senior Vice President at Hamilton Insurance Group. Prior to joining Hamilton, Mr.
Added
She joined White Mountains in 2003 and has served in a variety of accounting and audit-related positions with the Company and its subsidiaries. Prior to joining the Company, Ms. Hildreth spent 13 years with PricewaterhouseCoopers. Mr. Seelig is Executive Vice President and General Counsel of the Company. Since 2022, Mr. Seelig has also served as Head of Investor Relations.

Item 5. Market for Registrant's Common Equity

Market for Common Equity — stock, dividends, buybacks

4 edited+1 added−1 removed0 unchanged
Biggest changePurchases of Equity Securities by the Company The following table provides information regarding common shares repurchased by the Company during the fourth quarter of 2024: Months Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans (1) Maximum Number of Shares that May Yet Be Purchased Under the Plans (1) October 1 - October 31, 2024 — $ — — 301,014 November 1 - November 30, 2024 — $ — — 301,014 December 1 - December 31, 2024 — $ — — 301,014 Total — $ — — 301,014 (1) The Company’s Board of Directors has authorized it to repurchase its common shares, from time to time, subject to market conditions.
Biggest changePurchases of Equity Securities by the Company The following table provides information regarding common shares repurchased by the Company during the fourth quarter of 2025: Months Total Number of Shares Purchased Average Price Paid per Share Total Number of Shares Purchased as Part of Publicly Announced Plans (1) Maximum Number of Shares that May Yet Be Purchased Under the Plans (1) October 1 - October 31, 2025 20,005 $ 1,876.80 20,005 281,009 November 1 - November 30, 2025 11,415 $ 1,897.36 11,415 269,594 December 1 - December 31, 2025 (2) 64,064 $ 2,082.60 — 269,594 Total 95,484 $ 2,017.34 31,420 269,594 (1) The Company’s Board of Directors has authorized it to repurchase its common shares, from time to time, subject to market conditions.
For information on securities authorized for issuance under the Company’s equity compensation plans, see “ Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters ” on page 104 . The following graph presents the five-year cumulative total return for a shareholder who invested $100 in common shares as of December 31, 2019, assuming re-investment of dividends.
For information on securities authorized for issuance under the Company’s equity compensation plans, see “ Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters ” on page 104 . The following graph presents the five-year cumulative total return for a shareholder who invested $100 in common shares as of December 31, 2020, assuming re-investment of dividends.
Cumulative returns for the five-year period ended December 31, 2024 are also shown for the Standard & Poor’s 500 Stocks Capitalization Weighted Index (“S&P 500”) and the Standard & Poor’s 500 Stocks (Property & Casualty) Capitalization Weighted Index (“S&P P&C”) for comparison.
Cumulative returns for the five-year period ended December 31, 2025 are also shown for the Standard & Poor’s 500 Stocks Capitalization Weighted Index (“S&P 500”) and the Standard & Poor’s 500 Stocks (Property & Casualty) Capitalization Weighted Index (“S&P P&C”) for comparison.
Item 5. Market for the Company’s Common Equity, Related Shareholder Matters and Issuer Purchases of Equity Securities White Mountains’s common shares are listed on the New York Stock Exchange (symbol “WTM”) and the Bermuda Stock Exchange (symbol “WTM-BH”). As of February 24, 2025, there were 231 registered holders of White Mountains common shares, par value $1.00 per share.
Item 5. Market for the Company’s Common Equity, Related Shareholder Matters and Issuer Purchases of Equity Securities White Mountains’s common shares are listed on the New York Stock Exchange (symbol “WTM”) and the Bermuda Stock Exchange (symbol “WTM-BH”). As of February 23, 2026, there were 228 registered holders of White Mountains common shares, par value $1.00 per share.
Removed
The repurchase authorizations do not have a stated expiration date. Item 6. Reserved None. 44
Added
The repurchase authorizations do not have a stated expiration date. (2) On December 24, 2025, White Mountains completed a “modified Dutch auction” self-tender offer, through which it repurchased 64,064 of its common shares at a purchase price of $2,082.60 per share ($2,050.00 excluding expenses) for a total cost of approximately $133.4 million, including expenses. Item 6. Reserved None. 44

Item 6. [Reserved]

Selected Financial Data — reserved (removed by SEC in 2021)

1 edited+0 added−0 removed0 unchanged
Biggest changeITEM 6. Reserved 44 ITEM 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations 45 Results of Operations 45 Liquidity and Capital Resources 74 Transactions with Related Persons 79 Non-GAAP Financial Measures 79 Critical Accounting Estimates 81 Forward-Looking Statements 101 ITEM 7A. Quantitative and Qualitative Disclosures About Market Risk 101 ITEM 8.
Biggest changeITEM 6. Reserved 44 ITEM 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations 45 Results of Operations 45 Liquidity and Capital Resources 80 Transactions with Related Persons 85 Non-GAAP Financial Measures 85 Critical Accounting Estimates 87 Forward-Looking Statements 101 ITEM 7A. Quantitative and Qualitative Disclosures About Market Risk 102 ITEM 8.

Item 7. Management's Discussion & Analysis

Management's Discussion & Analysis (MD&A) — revenue / margin commentary

267 edited+108 added−77 removed106 unchanged
Biggest changeThe resulting ratios are weighted using cumulative incurred loss and LAE as of December 31, 2024. 88 Property and Accident & Health $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 19.1 $ 18.1 $ 17.2 $ 16.2 $ 16.0 $ 16.0 $ 15.8 $ 15.7 $ 16.0 $ 16.1 $ .1 2,829 2016 22.2 17.5 18.2 18.4 18.3 18.5 18.5 18.5 18.5 .2 3,433 2017 31.1 37.7 45.2 44.2 42.8 42.3 43.8 43.4 15.8 4,624 2018 40.7 47.1 49.0 46.7 46.8 46.3 46.4 1.9 4,288 2019 33.9 31.2 27.0 23.8 23.2 22.8 .6 4,024 2020 76.9 75.1 74.5 77.6 79.5 9.9 4,646 2021 170.0 153.7 165.3 168.0 7.5 3,509 2022 241.5 266.9 277.3 12.9 4,044 2023 213.9 176.1 77.3 3,598 2024 359.5 202.7 3,614 Total $ 1,207.6 Property and Accident & Health Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 6.9 $ 12.2 $ 13.4 $ 14.6 $ 14.5 $ 14.8 $ 15.0 $ 15.0 $ 15.4 $ 15.6 2016 8.5 13.0 16.3 16.7 16.8 17.1 17.7 17.9 18.1 2017 16.8 25.7 31.5 32.7 29.4 27.1 25.4 28.2 2018 15.6 32.2 40.1 40.0 40.8 42.8 43.6 2019 6.8 16.7 18.3 18.5 19.3 20.6 2020 11.2 33.9 46.9 55.6 66.5 2021 30.7 86.5 129.8 142.7 2022 69.4 191.9 229.4 2023 19.9 52.9 2024 54.8 Total 672.4 All outstanding liabilities before 2015, net of reinsurance 1.5 Loss and LAE reserves, net of reinsurance $ 536.7 Property and Accident & Health Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 23.8% 32.8% 18.3% 6.4% 2.8% 1.3% 0.5% 0.8% 0.1% 0.1% 89 Property and Accident & Health $ in Millions Incurred Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 53.8 $ 51.0 $ 47.7 $ 45.3 $ 44.7 $ 44.9 $ 44.4 $ 44.2 $ 44.5 $ 44.6 $ .1 2,829 2016 59.4 47.2 49.0 49.4 49.3 49.8 49.8 49.8 49.8 .2 3,433 2017 56.5 73.1 91.9 89.5 86.1 85.3 86.7 86.3 15.8 4,624 2018 88.6 103.7 108.1 102.7 102.9 102.4 102.5 1.9 4,288 2019 71.4 64.9 54.8 49.3 48.7 48.3 .6 4,024 2020 122.5 119.1 118.2 121.3 123.2 9.9 4,646 2021 191.3 170.1 181.7 184.4 7.5 3,509 2022 241.9 267.4 277.8 12.9 4,044 2023 213.9 176.1 77.3 3,598 2024 359.5 202.7 3,614 Total $ 1,452.5 Property and Accident & Health Millions Cumulative Paid Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 18.7 $ 35.7 $ 39.6 $ 42.5 $ 42.4 $ 43.0 $ 43.5 $ 43.5 $ 43.9 $ 44.1 2016 24.2 37.9 46.1 46.9 47.2 47.9 49.0 49.2 49.3 2017 42.6 64.6 79.0 81.8 74.1 70.1 68.3 71.1 2018 37.4 77.2 95.6 95.5 96.9 98.9 99.7 2019 16.2 39.8 43.7 43.9 44.7 46.0 2020 24.0 67.9 90.6 99.3 110.3 2021 38.7 102.9 146.2 159.2 2022 69.9 192.4 229.9 2023 19.9 52.9 2024 54.8 Total 917.3 All outstanding liabilities before 2015, gross of amounts attributable to TPC Providers 1.5 Loss and LAE reserves, gross of amounts attributable to TPC Providers $ 536.7 Property and Accident & Health Average Annual Percentage Payout of Incurred Loss and LAE by Age, Gross of Amounts Attributable to TPC Providers Years 1 2 3 4 5 6 7 8 9 10 26.1% 34.1% 17.7% 5.4% 1.8% 1.2% 1.3% 0.9% 0.1% 0.1% 90 Marine & Energy $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 21.7 $ 17.4 $ 16.1 $ 13.3 $ 12.7 $ 12.8 $ 12.7 $ 12.9 $ 12.7 $ 12.7 $ — 3,243 2016 23.4 19.5 15.6 14.6 14.3 14.8 14.1 13.6 13.3 — 3,772 2017 26.0 19.3 17.6 16.9 16.6 15.8 16.0 16.1 .4 4,139 2018 25.4 19.9 17.4 17.8 17.3 17.7 16.7 .2 3,238 2019 23.7 21.6 21.6 21.4 21.9 21.2 .5 2,393 2020 29.7 27.1 28.5 27.4 27.1 .8 1,582 2021 86.2 69.3 67.3 74.5 4.0 1,505 2022 149.7 153.6 156.0 31.9 1,968 2023 197.0 188.2 115.9 2,138 2024 239.9 182.6 1,485 Total $ 765.7 Marine & Energy Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 4.0 $ 7.8 $ 9.6 $ 11.0 $ 10.4 $ 10.5 $ 10.9 $ 11.5 $ 11.6 $ 11.6 2016 5.5 10.0 12.6 13.0 13.1 13.7 13.4 13.4 13.4 2017 5.1 11.1 12.8 14.0 14.1 14.1 14.0 14.3 2018 2.6 12.4 13.9 14.6 15.3 15.3 15.4 2019 3.3 10.6 12.6 14.3 15.3 18.1 2020 3.1 12.7 16.0 18.5 21.9 2021 6.3 24.3 38.2 51.9 2022 12.2 66.2 97.7 2023 10.5 42.1 2024 20.9 Total 307.3 All outstanding liabilities before 2015, net of reinsurance 4.7 Loss and LAE reserves, net of reinsurance $ 463.1 Marine & Energy Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 12.9% 30.5% 19.5% 8.0% 4.9% 6.9% 0.3% 0.4% (0.3)% 0.1% 91 Marine & Energy $ in Millions Incurred Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 59.9 $ 46.2 $ 42.1 $ 35.1 $ 33.6 $ 33.9 $ 33.6 $ 34.0 $ 33.8 $ 33.8 $ — 3,243 2016 62.2 50.9 41.3 38.6 37.9 39.2 37.9 37.5 37.2 — 3,772 2017 61.7 45.0 40.7 39.1 38.4 36.9 37.2 37.3 .4 4,139 2018 57.7 44.7 38.7 39.6 38.8 39.2 38.3 .2 3,238 2019 45.5 40.4 40.5 40.1 40.6 39.9 .5 2,393 2020 46.5 41.9 44.3 43.2 43.0 .8 1,582 2021 93.6 73.3 71.2 78.5 4.0 1,505 2022 149.9 153.8 156.2 31.9 1,968 2023 197.0 188.2 115.9 2,138 2024 239.9 182.6 1,485 Total $ 892.3 Marine & Energy Millions Cumulative Paid Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 10.2 $ 22.5 $ 28.4 $ 31.8 $ 30.4 $ 30.5 $ 31.5 $ 32.6 $ 32.6 $ 32.7 2016 16.5 28.6 35.0 36.1 36.4 37.8 37.3 37.3 37.3 2017 13.1 27.9 32.2 35.2 35.2 35.2 35.2 35.5 2018 6.5 30.3 34.0 35.7 36.8 36.8 37.0 2019 7.9 25.3 30.0 33.0 34.0 36.7 2020 6.7 26.0 31.9 34.4 37.8 2021 7.6 28.3 42.2 56.1 2022 12.4 66.3 97.8 2023 10.5 42.1 2024 20.9 Total 433.9 All outstanding liabilities before 2015, gross of amounts attributable to TPC Providers 4.7 Loss and LAE reserves, gross of amounts attributable to TPC Providers $ 463.1 Marine & Energy Average Annual Percentage Payout of Incurred Loss and LAE by Age, Gross of Amounts Attributable to TPC Providers Years 1 2 3 4 5 6 7 8 9 10 14.7% 32.6% 18.4% 7.8% 4.0% 5.7% 0.7% 0.5% (0.1)% 0.3% 92 Specialty $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 17.3 $ 14.6 $ 12.3 $ 10.7 $ 11.0 $ 11.2 $ 11.1 $ 8.9 $ 8.1 $ 11.3 $ .3 1,841 2016 18.2 14.3 10.9 11.3 11.8 11.8 8.9 8.5 12.3 .4 1,936 2017 17.9 12.8 11.9 11.4 11.6 10.6 10.3 10.9 .4 2,195 2018 14.4 16.2 16.6 15.9 14.8 15.7 16.6 .4 2,122 2019 21.6 19.4 18.6 25.6 30.1 19.9 .3 2,387 2020 23.7 22.8 18.6 19.5 16.7 .9 2,017 2021 70.3 62.1 51.4 43.8 10.0 1,725 2022 180.3 174.8 168.4 77.0 1,496 2023 214.5 197.4 94.4 1,641 2024 218.7 141.6 1,292 Total $ 716.0 Specialty Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 4.0 $ 7.0 $ 7.6 $ 8.0 $ 8.0 $ 8.1 $ 8.1 $ 6.4 $ 6.2 $ 9.3 2016 3.2 7.9 9.1 9.9 10.3 10.3 8.5 8.3 11.7 2017 3.1 6.5 8.3 8.5 8.5 9.2 8.9 9.6 2018 2.7 8.2 9.9 10.4 11.8 13.0 14.1 2019 4.8 6.9 7.4 18.2 25.1 17.6 2020 5.0 10.5 12.9 17.7 17.7 2021 5.0 23.9 35.5 34.6 2022 16.0 61.7 82.5 2023 18.4 75.2 2024 27.3 Total 299.6 All outstanding liabilities before 2015, net of reinsurance .6 Loss and LAE reserves, net of reinsurance $ 417.0 Specialty Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 19.3% 30.8% 10.9% 4.9% 7.3% 2.5% 1.5% 1.8% (1.3)% 1.1% 93 Specialty $ in Millions Incurred Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 46.5 $ 39.0 $ 31.2 $ 27.2 $ 27.9 $ 28.4 $ 28.3 $ 24.3 $ 23.5 $ 26.7 $ .3 1,841 2016 51.2 38.7 30.5 31.3 32.7 32.6 27.6 27.1 30.9 .4 1,936 2017 41.5 29.0 26.7 25.6 26.0 24.2 23.9 24.5 .4 2,195 2018 29.0 33.2 34.3 32.5 30.5 31.4 32.3 .4 2,122 2019 38.8 33.6 31.7 43.9 48.4 38.3 .3 2,387 2020 42.4 41.2 33.9 34.8 32.0 .9 2,017 2021 80.2 65.9 55.2 47.6 10.0 1,725 2022 180.5 175.0 168.5 77.0 1,496 2023 214.5 197.4 94.4 1,641 2024 218.7 141.6 1,292 Total $ 816.9 Specialty Millions Cumulative Paid Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 12.1 $ 21.5 $ 23.5 $ 24.5 $ 24.7 $ 24.8 $ 24.8 $ 21.8 $ 21.7 $ 24.7 2016 9.9 24.4 27.2 29.2 30.2 30.3 27.2 26.9 30.3 2017 8.3 16.8 21.3 21.6 21.6 22.8 22.6 23.2 2018 6.7 20.0 24.0 25.1 27.5 28.7 29.7 2019 11.5 16.5 17.7 36.6 43.5 36.0 2020 11.5 24.0 28.2 33.0 33.0 2021 5.9 27.7 39.3 38.4 2022 16.2 61.9 82.7 2023 18.4 75.2 2024 27.3 Total 400.5 All outstanding liabilities before 2015, gross of amounts attributable to TPC Providers .6 Loss and LAE reserves, gross of amounts attributable to TPC Providers $ 417.0 Specialty Average Annual Percentage Payout of Incurred Loss and LAE by Age, Gross of Amounts Attributable to TPC Providers Years 1 2 3 4 5 6 7 8 9 10 21.2% 32.3% 10.8% 6.4% 6.2% 3.0% 1.3% 0.9% (2.1)% 0.2% 94 Casualty-Active $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 9.6 $ 9.7 $ 8.2 $ 8.1 $ 7.4 $ 7.1 $ 7.0 $ 7.3 $ 7.5 $ 7.4 $ .5 1,306 2016 8.8 8.3 8.9 9.0 9.1 9.2 9.2 10.1 11.8 .5 1,588 2017 11.5 11.7 10.8 9.3 9.0 10.5 10.6 10.9 .8 1,667 2018 12.9 13.3 11.1 10.8 8.6 9.1 9.4 1.1 1,147 2019 14.8 13.7 12.3 10.6 11.4 13.0 1.7 1,019 2020 13.5 12.0 10.8 9.2 8.8 2.0 665 2021 21.4 22.4 16.6 16.3 6.4 961 2022 32.9 38.0 34.6 27.9 1,558 2023 60.9 65.9 57.4 1,792 2024 59.5 54.9 1,170 Total $ 237.6 Casualty-Active Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 1.8 $ 2.4 $ 3.2 $ 4.4 $ 4.7 $ 4.9 $ 5.1 $ 5.5 $ 6.1 $ 6.3 2016 .2 1.0 2.3 4.0 4.6 5.3 6.5 8.1 9.7 2017 .8 1.7 2.7 3.4 4.2 5.7 7.5 8.3 2018 .3 1.4 3.5 4.3 4.3 6.2 7.1 2019 .3 1.4 2.3 3.0 5.7 8.3 2020 .5 1.0 2.0 3.3 5.3 2021 .5 .9 3.1 9.6 2022 .4 1.5 2.4 2023 .9 5.6 2024 1.9 Total 64.5 All outstanding liabilities before 2015, net of reinsurance 4.9 Loss and LAE reserves, net of reinsurance $ 178.0 Casualty-Active Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 4.4% 8.4% 11.6% 14.4% 9.5% 11.7% 6.3% 4.8% 3.7% 3.1% 95 Casualty-Active $ in Millions Incurred Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 20.2 $ 21.0 $ 16.0 $ 15.6 $ 13.8 $ 13.3 $ 13.0 $ 13.4 $ 13.7 $ 13.6 $ .5 1,306 2016 17.7 16.2 17.8 18.0 18.2 18.4 18.5 19.4 21.1 .5 1,588 2017 21.8 22.1 19.9 16.4 15.7 18.3 18.4 18.7 .8 1,667 2018 23.4 24.3 19.1 18.5 14.6 15.1 15.4 1.1 1,147 2019 23.2 20.6 17.4 14.3 15.1 16.8 1.7 1,019 2020 18.4 15.0 12.9 11.3 10.9 2.0 665 2021 22.7 23.1 17.3 17.0 6.4 961 2022 33.0 38.0 34.7 27.9 1,558 2023 60.9 65.9 57.4 1,792 2024 59.5 54.9 1,170 Total $ 273.6 Casualty-Active Millions Cumulative Paid Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 2.0 $ 3.6 $ 6.3 $ 9.2 $ 10.0 $ 10.5 $ 11.1 $ 11.6 $ 12.3 $ 12.5 2016 .7 3.2 6.4 10.6 11.9 13.7 15.8 17.4 19.0 2017 2.6 4.8 7.5 9.1 10.8 13.5 15.3 16.2 2018 .8 3.5 8.5 10.3 10.3 12.2 13.1 2019 .8 3.3 5.6 6.8 9.4 12.0 2020 1.1 2.4 4.1 5.4 7.4 2021 1.0 1.6 3.8 10.3 2022 .5 1.6 2.5 2023 .9 5.6 2024 1.9 Total 100.5 All outstanding liabilities before 2015, gross of amounts attributable to TPC Providers 4.9 Loss and LAE reserves, gross of amounts attributable to TPC Providers $ 178.0 Casualty-Active Average Annual Percentage Payout of Incurred Loss and LAE by Age, Gross of Amounts Attributable to TPC Providers Years 1 2 3 4 5 6 7 8 9 10 5.0% 9.5% 13.8% 14.6% 9.8% 12.4% 6.7% 4.6% 3.3% 4.1% 96 Casualty-Runoff $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 36.4 $ 31.9 $ 33.1 $ 36.6 $ 36.3 $ 37.3 $ 36.7 $ 39.1 $ 40.2 $ 39.4 $ 1.9 1,950 2016 32.4 32.1 40.3 38.4 38.7 38.4 37.6 37.3 37.4 2.0 2,150 2017 30.5 33.8 31.3 32.0 31.5 29.8 28.2 28.4 2.3 1,604 2018 33.5 28.1 27.2 26.5 26.1 27.9 27.7 3.4 1,280 2019 26.4 23.2 23.3 24.8 23.5 23.6 5.2 973 2020 15.8 12.2 13.8 10.9 9.5 2.9 567 2021 10.4 7.0 5.4 4.5 1.8 283 2022 .8 2.6 2.5 1.6 80 2023 2.7 3.6 2.4 40 2024 1.3 .7 22 Total $ 177.9 Casualty-Runoff Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 4.3 $ 8.2 $ 14.5 $ 21.4 $ 24.6 $ 27.3 $ 28.9 $ 33.0 $ 35.3 $ 35.8 2016 3.9 10.1 17.7 22.7 25.3 27.8 28.7 30.9 32.4 2017 3.2 9.4 14.6 18.4 21.3 22.5 22.8 23.5 2018 3.4 7.4 12.6 14.9 16.2 18.2 21.3 2019 3.3 5.8 7.8 12.1 15.1 15.8 2020 .8 1.3 3.1 6.0 6.3 2021 .5 1.7 1.8 2.3 2022 .3 .5 .7 2023 .9 1.0 2024 .5 Total 139.6 All outstanding liabilities before 2015, net of reinsurance 28.2 Loss and LAE reserves, net of reinsurance $ 66.5 Casualty-Runoff Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 8.8% 14.1% 15.6% 14.8% 8.5% 6.8% 5.9% 4.1% 3.1% 2.0% 97 Casualty-Runoff $ in Millions Incurred Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, As of December 31, 2024 Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2015 $ 84.9 $ 72.3 $ 76.2 $ 84.8 $ 84.1 $ 86.5 $ 84.9 $ 89.2 $ 90.3 $ 89.4 $ 1.9 1,950 2016 74.2 71.0 91.3 86.7 87.3 86.6 85.1 84.9 84.9 2.0 2,150 2017 63.6 71.9 65.6 67.2 65.9 63.0 61.5 61.6 2.3 1,604 2018 66.3 52.6 50.6 48.9 48.2 50.0 49.9 3.4 1,280 2019 43.7 36.1 36.4 38.9 37.7 37.8 5.2 973 2020 22.1 14.0 16.8 13.9 12.5 2.9 567 2021 14.7 8.6 7.1 6.1 1.8 283 2022 1.0 2.8 2.8 1.6 80 2023 2.7 3.6 2.4 40 2024 1.3 .7 22 Total $ 349.9 Casualty-Runoff Millions Cumulative Paid Loss and LAE, Gross of Amounts Attributable to TPC Providers For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2015 $ 7.4 $ 19.5 $ 40.6 $ 57.6 $ 65.8 $ 72.0 $ 75.9 $ 83.1 $ 85.4 $ 85.8 2016 11.9 31.4 50.0 62.6 68.8 74.7 76.3 78.5 80.0 2017 9.4 24.7 37.8 46.8 53.7 55.7 56.0 56.7 2018 8.4 18.3 30.5 36.0 38.3 40.3 43.4 2019 8.1 14.0 18.7 26.3 29.3 30.0 2020 1.8 3.0 6.0 9.0 9.3 2021 1.3 3.3 3.5 3.9 2022 .6 .8 1.0 2023 .9 1.0 2024 .5 Total 311.6 All outstanding liabilities before 2015, gross of amounts attributable to TPC Providers 28.2 Loss and LAE reserves, gross of amounts attributable to TPC Providers $ 66.5 Casualty-Runoff Average Annual Percentage Payout of Incurred Loss and LAE by Age, Gross of Amounts Attributable to TPC Providers Years 1 2 3 4 5 6 7 8 9 10 9.4% 14.6% 17.2% 16.4% 9.0% 6.7% 5.1% 4.8% 3.9% 2.3% 98 The following tables provide a reconciliation from the first table grouping above, presented net of reinsurance, and the second table grouping above, presented gross of amounts attributable to TPC Providers: December 31, 2024 Cumulative Incurred Loss and LAE Millions Net of Reinsurance Amounts Attributable to TPC Providers Gross of Amounts Attributable to TPC Providers Property and Accident & Health $ 1,207.6 $ 244.9 $ 1,452.5 Marine & Energy 765.7 126.6 892.3 Specialty 716.0 100.9 816.9 Casualty-Active 237.6 36.0 273.6 Casualty-Runoff 177.9 172.0 349.9 Total $ 3,104.8 $ 680.4 $ 3,785.2 December 31, 2024 Cumulative Paid Loss and LAE Millions Net of Reinsurance Amounts Attributable to TPC Providers Gross of Amounts Attributable to TPC Providers Property and Accident & Health $ 672.4 $ 244.9 $ 917.3 Marine & Energy 307.3 126.6 433.9 Specialty 299.6 100.9 400.5 Casualty-Active 64.5 36.0 100.5 Casualty-Runoff 139.6 172.0 311.6 Total $ 1,483.4 $ 680.4 $ 2,163.8 December 31, 2024 Loss and LAE Reserves Millions Net of Reinsurance Amounts Attributable to TPC Providers Gross of Amounts Attributable to TPC Providers Property and Accident & Health $ 536.7 $ — $ 536.7 Marine & Energy 463.1 — 463.1 Specialty 417.0 — 417.0 Casualty-Active 178.0 — 178.0 Casualty-Runoff 66.5 — 66.5 Total $ 1,661.3 $ — $ 1,661.3 99 3.
Biggest changeThe resulting ratios are weighted using cumulative incurred loss and LAE as of December 31, 2025. 94 Property and Accident & Health $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2025 Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2016 $ 22.7 $ 17.8 $ 18.6 $ 18.7 $ 18.7 $ 18.9 $ 18.8 $ 18.8 $ 18.8 $ 18.8 $ .2 3,434 2017 31.6 38.3 45.8 44.8 43.4 42.9 44.3 43.9 43.3 15.6 4,629 2018 41.4 47.8 49.7 47.4 47.4 47.0 47.0 49.0 2.7 4,293 2019 34.6 31.7 27.4 24.2 23.5 23.2 21.5 .5 4,030 2020 78.1 76.3 75.3 79.1 81.0 84.8 6.0 4,664 2021 173.0 156.8 168.9 171.5 169.7 8.1 3,533 2022 245.7 269.6 280.0 281.9 9.0 4,100 2023 216.9 178.6 130.4 20.8 3,688 2024 364.8 324.6 106.4 4,495 2025 394.1 171.7 3,899 Total $ 1,518.1 Property and Accident & Health Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2016 $ 8.6 $ 13.3 $ 16.6 $ 17.0 $ 17.1 $ 17.4 $ 18.0 $ 18.2 $ 18.4 $ 18.4 2017 17.0 26.1 31.9 33.1 29.9 27.7 25.9 28.7 29.3 2018 15.8 32.7 40.6 40.6 41.4 43.4 44.2 45.2 2019 6.9 17.0 18.6 18.8 19.6 20.9 19.9 2020 11.4 34.5 47.5 56.3 67.4 72.4 2021 31.0 87.5 132.3 145.6 150.9 2022 71.7 194.5 232.0 250.2 2023 20.2 53.8 78.5 2024 55.4 134.6 2025 142.8 Total 942.2 All outstanding liabilities before 2016, net of reinsurance 2.4 Loss and LAE reserves, net of reinsurance $ 578.3 Property and Accident & Health Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 27.4% 31.9% 18.4% 6.4% 2.9% 1.9% 0.4% 0.9% 0.2% 0.1% 95 Marine & Energy $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2025 Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2016 $ 23.8 $ 20.0 $ 16.0 $ 14.9 $ 14.6 $ 15.2 $ 14.5 $ 14.0 $ 13.7 $ 13.8 $ — 3,776 2017 26.5 19.7 17.9 17.3 16.9 16.0 16.3 16.4 16.4 .2 4,141 2018 26.2 20.6 18.1 18.5 18.0 18.4 17.4 17.0 .2 3,245 2019 24.2 22.0 22.1 21.9 22.3 21.6 21.8 .4 2,413 2020 30.4 27.7 29.1 27.9 27.6 27.6 .8 1,594 2021 87.7 70.5 68.4 75.6 79.8 3.8 1,530 2022 150.8 154.9 157.5 218.6 56.8 2,083 2023 198.6 189.9 123.2 36.8 2,341 2024 243.3 248.1 138.4 2,195 2025 235.3 184.9 1,618 Total $ 1,001.6 Marine & Energy Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2016 $ 5.6 $ 10.2 $ 12.9 $ 13.3 $ 13.4 $ 14.1 $ 13.8 $ 13.8 $ 13.8 $ 13.8 2017 5.2 11.3 13.1 14.4 14.4 14.3 14.3 14.6 15.9 2018 2.7 12.9 14.6 15.3 16.0 15.9 16.1 16.3 2019 3.4 10.9 12.9 14.7 15.7 18.4 19.3 2020 3.2 12.9 16.3 18.9 22.4 23.2 2021 6.4 24.9 38.9 52.7 64.4 2022 12.3 66.7 98.6 145.5 2023 10.6 42.7 61.3 2024 21.4 60.1 2025 19.4 Total 439.2 All outstanding liabilities before 2016, net of reinsurance 6.6 Loss and LAE reserves, net of reinsurance $ 569.0 Marine & Energy Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 12.1% 27.1% 17.3% 12.1% 6.4% 6.5% 0.5% 0.4% 0.1% 0.1% 96 Specialty $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2025 Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2016 $ 18.5 $ 14.5 $ 11.1 $ 11.4 $ 12.0 $ 12.0 $ 9.1 $ 8.6 $ 12.5 $ 12.2 $ .2 1,936 2017 18.3 13.2 12.3 11.8 11.9 10.9 10.6 11.2 11.1 — 2,201 2018 14.7 16.6 17.0 16.2 15.1 15.9 16.9 17.5 .9 2,129 2019 22.1 19.8 18.9 25.9 30.1 20.0 26.8 .7 2,396 2020 24.5 23.5 19.3 20.4 17.3 17.7 1.3 2,028 2021 71.8 63.0 51.8 44.0 41.7 6.6 1,735 2022 181.9 178.5 172.6 179.6 58.3 1,577 2023 216.6 199.4 153.4 41.3 1,734 2024 223.2 231.3 133.2 1,798 2025 226.8 169.4 1,831 Total $ 918.1 Specialty Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2016 $ 3.2 $ 8.0 $ 9.2 $ 10.0 $ 10.4 $ 10.5 $ 8.7 $ 8.4 $ 11.8 $ 11.8 2017 3.3 6.8 8.6 8.8 8.8 9.5 9.3 9.9 9.9 2018 2.9 8.5 10.2 10.6 12.0 13.2 14.4 14.8 2019 5.0 7.2 7.6 18.5 25.2 17.7 19.8 2020 5.4 11.0 13.4 18.8 18.5 19.2 2021 5.1 24.1 35.8 34.6 35.3 2022 16.1 62.5 84.9 113.2 2023 19.2 76.3 109.1 2024 28.9 53.8 2025 24.1 Total 411.0 All outstanding liabilities before 2016, net of reinsurance 1.1 Loss and LAE reserves, net of reinsurance $ 508.2 Specialty Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 18.2% 26.8% 13.2% 8.7% 6.3% 2.5% 2.1% 1.8% (1.2)% 1.0% 97 Casualty-Active $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2025 Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2016 $ 8.8 $ 8.3 $ 8.9 $ 9.0 $ 9.1 $ 9.2 $ 9.2 $ 10.1 $ 11.8 $ 11.9 $ .4 1,606 2017 11.6 11.7 10.8 9.3 9.1 10.5 10.7 10.9 10.6 .7 1,693 2018 12.9 13.3 11.1 10.9 8.6 9.2 9.4 10.5 .9 1,175 2019 14.8 13.7 12.3 10.6 11.4 13.0 14.4 1.4 1,062 2020 13.5 12.1 10.9 9.2 8.8 9.5 1.7 731 2021 21.4 22.4 16.6 16.3 21.7 4.1 1,050 2022 33.0 38.1 34.7 17.3 9.8 1,774 2023 61.0 65.9 57.1 39.4 2,234 2024 60.0 82.0 71.9 2,171 2025 68.2 63.4 1,723 Total $ 303.2 Casualty-Active Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2016 $ .2 $ 1.0 $ 2.3 $ 4.0 $ 4.6 $ 5.3 $ 6.5 $ 8.1 $ 9.7 $ 10.3 2017 .8 1.7 2.8 3.4 4.2 5.7 7.5 8.3 9.1 2018 .3 1.4 3.5 4.3 4.3 6.2 7.1 8.0 2019 .3 1.4 2.3 3.0 5.7 8.3 10.2 2020 .5 1.0 2.0 3.3 5.3 6.0 2021 .5 .9 3.1 9.6 12.6 2022 .5 1.6 2.5 3.6 2023 .9 5.6 10.8 2024 1.9 4.6 2025 1.0 Total 76.2 All outstanding liabilities before 2016, net of reinsurance 3.6 Loss and LAE reserves, net of reinsurance $ 230.6 Casualty-Active Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 3.8% 7.5% 11.4% 12.9% 10.0% 11.2% 7.2% 5.1% 4.2% 3.4% 98 Casualty-Runoff $ in Millions Incurred Loss and LAE, Net of Reinsurance For the Years Ended December 31, As of December 31, 2025 Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Total IBNR plus expected development on reported claims Cumulative number of reported claims 2016 $ 32.6 $ 32.3 $ 40.5 $ 38.6 $ 38.9 $ 38.6 $ 37.7 $ 37.5 $ 37.5 $ 38.1 $ 1.9 2,156 2017 30.7 34.0 31.5 32.1 31.6 29.9 28.3 28.5 27.9 2.0 1,606 2018 33.6 28.2 27.3 26.6 26.2 28.0 27.8 28.2 2.9 1,284 2019 26.5 23.3 23.4 24.9 23.6 23.7 22.5 4.2 976 2020 15.9 12.3 13.9 10.9 9.5 9.2 2.3 573 2021 10.5 7.0 5.5 4.5 3.9 1.5 284 2022 .8 2.6 2.6 2.3 1.3 80 2023 2.7 3.6 3.1 1.8 40 2024 1.2 1.1 .5 20 2025 .7 — 41 Total $ 137.0 Casualty-Runoff Millions Cumulative Paid Loss and LAE, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2016 $ 3.9 $ 10.2 $ 17.7 $ 22.7 $ 25.4 $ 27.8 $ 28.8 $ 31.0 $ 32.5 $ 34.1 2017 3.2 9.4 14.7 18.5 21.4 22.5 22.8 23.5 24.8 2018 3.4 7.4 12.6 14.9 16.3 18.2 21.3 22.7 2019 3.3 5.8 7.8 12.1 15.1 15.9 17.3 2020 .8 1.3 3.1 6.0 6.3 6.5 2021 .5 1.7 1.9 2.3 2.4 2022 .3 .6 .7 .9 2023 .9 1.0 1.1 2024 .5 .5 2025 .6 Total 110.9 All outstanding liabilities before 2016, net of reinsurance 31.0 Loss and LAE reserves, net of reinsurance $ 57.1 Casualty-Runoff Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 8.8% 13.9% 15.3% 14.8% 8.5% 6.7% 5.9% 4.2% 3.2% 2.2% 99 3.
Ark’s combined ratio included four points of net favorable prior year development in 2024, driven primarily by the specialty and property lines of business, compared to two points of net unfavorable prior year development in 2023, driven primarily by Hurricane Ian and Winter Storm Elliott, partially offset by net favorable prior year loss reserve development within the specialty and casualty–runoff reserving lines of business.
Ark’s combined ratio included four points of net favorable prior year development in 2024, driven primarily by specialty and property lines of business, compared to two points of net unfavorable prior year development in 2023, driven primarily by Hurricane Ian and Winter Storm Elliott, partially offset by net favorable prior year loss reserve development within the specialty and casualty–runoff reserving lines of business.
Ark’s results included net realized and unrealized investment gains of $50 million in 2024, driven primarily by net unrealized investment gains on other long-term investments and common equity securities, partially offset by foreign currency losses, compared to $86 million in 2023, driven primarily by net unrealized investment gains on other long-term investments, fixed maturity investments and common equity securities.
Ark’s results included net realized and unrealized investment gains (losses) of $50 million in 2024, driven primarily by net unrealized investment gains on other long-term investments and common equity securities, partially offset by net foreign currency losses, compared to $86 million in 2023, driven primarily by net unrealized investment gains on other long-term investments, fixed maturity investments and common equity securities.
The decrease in fair value of $5 million was driven by a $22 million cash payment of principal and interest, partially offset by $16 million of accrued interest and a $1 million increase in fair value as a result of lower market interest rates.
The decrease in fair value of $5 million was driven by a $22 million cash payment of principal and interest, partially offset by $16 million of accrued interest and a $1 million increase in fair value as a result of lower market interest rates.
White Mountains’s Other Operations reported general and administrative expenses of $170 million in 2024 compared to $182 million in 2023. Other Operations general and administrative expenses in 2024 included $92 million of parent company compensation and benefits compared to $94 million in 2023.
White Mountains’s Other Operations reported general and administrative expenses of $170 million in 2024 compared to $182 million in 2023. General and administrative expenses included $92 million of parent company compensation and benefits in 2024 compared to $94 million in 2023.
Investment returns for 2023 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, net realized and unrealized investment gains from private equity funds, hedge funds and unconsolidated entities, as well as unrealized gains from ILS funds.
Returns for 2023 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, net realized and unrealized investment gains from private equity funds, hedge funds and unconsolidated entities, as well as net investment income and unrealized gains from ILS funds.
The Pillar Two initiative includes a set of model rules that are generally designed to impose a top-up tax on a large multinational enterprise group to the extent the group is not subject to an effective tax rate of at least 15% in each jurisdiction in which the group has a consolidated affiliate or permanent establishment.
The Pillar Two initiative includes a set of model rules that are generally designed to impose a top-up tax on a large multinational enterprise group to the extent that the group is not subject to an effective tax rate of at least 15% in each jurisdiction in which the group has a consolidated affiliate or permanent establishment.
Of these payments, $21 million was a repayment of principal held in the Supplemental Trust, $1 million was a payment of accrued interest held in the Supplemental Trust and $8 million was a payment of accrued interest held outside the Supplemental Trust.
Of these payments, $21 million was a repayment of principal held in the Supplemental Trust, $1 million was a payment of accrued interest held in the Supplemental Trust and $8 million was a payment of accrued interest held outside the Supplemental Trust.
These forward-looking statements include, among others, statements with respect to White Mountains’s: • change in book value per share, adjusted book value per share or return on equity; • business strategy; • financial and operating targets or plans; • incurred loss and LAE and the adequacy of its loss and LAE reserves and related reinsurance; • projections of revenues, income (or loss), earnings (or loss) per share, EBITDA, adjusted EBITDA, dividends, market share or other financial forecasts of White Mountains or its businesses; • expansion and growth of its business and operations; and • future capital expenditures.
These forward-looking statements include, among others, statements with respect to White Mountains’s: • change in book value per share or return on equity; • business strategy; • financial and operating targets or plans; • incurred loss and LAE and the adequacy of its loss and LAE reserves and related reinsurance; • projections of revenues, income (or loss), earnings (or loss) per share, EBITDA, adjusted EBITDA, dividends, market share or other financial forecasts of White Mountains or its businesses; • expansion and growth of its business and operations; and • future capital expenditures.
The increase in gross written premiums was across all lines of business but driven primarily by structured property transactions placed in Bermuda and the addition of new products and teams, including accident & health, marine liability and political violence. The risk adjusted rate change on the Outrigger Re Ltd. portfolio of global property reinsurance was -3% in 2024.
The increase in gross written premiums was across all lines of business but driven primarily by structured property transactions placed in Bermuda and the addition of new products and underwriting teams, including accident & health, marine liability and political violence. The risk adjusted rate change on the Outrigger Re Ltd. portfolio of global property reinsurance was -3% in 2024.
During the fourth quarter of 2022, Ark sponsored the formation of Outrigger Re Ltd. to provide collateralized reinsurance protection on Ark’s Bermuda global property catastrophe excess of loss portfolio written in the 2023 underwriting year. Ark renewed its quota share reinsurance agreement with Outrigger Re Ltd. for the 2024 and 2025 underwriting years.
During the fourth quarter of 2022, Ark sponsored the formation of Outrigger Re Ltd. to provide collateralized reinsurance protection on Ark’s Bermuda global property catastrophe excess of loss portfolio written in the 2023 underwriting year. Ark renewed its quota share reinsurance agreement with Outrigger Re Ltd. for the 2024, 2025 and 2026 underwriting years.
On an ongoing basis, management evaluates its estimates and bases its estimates on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. 81 1.
On an ongoing basis, management evaluates its estimates and bases its estimates on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. 1.
Management believes that White Mountains’s cash balances, cash flows from operations and routine sales and maturities of investments are adequate to meet expected cash requirements for the foreseeable future at both a holding company and insurance, reinsurance and other operating subsidiary level. 74 Dividend Capacity Following is a description of the dividend capacity of White Mountains’s insurance and reinsurance and other operating subsidiaries: Ark/WM Outrigger During any 12-month period, GAIL, a class 4 licensed Bermuda insurer, has the ability to (i) make capital distributions of up to 15% of its total statutory capital per the previous year’s statutory financial statements or (ii) make dividend payments of up to 25% of its total statutory capital and surplus per the previous year’s statutory financial statements, without prior approval of Bermuda regulatory authorities.
Management believes that White Mountains’s cash balances, cash flows from operations and routine sales and maturities of investments are adequate to meet expected cash requirements for the foreseeable future at both a holding company and insurance, reinsurance and other operating subsidiary level. 80 Dividend Capacity Following is a description of the dividend capacity of White Mountains’s insurance and reinsurance and other operating subsidiaries: Ark/WM Outrigger During any 12-month period, GAIL, a class 4 licensed Bermuda insurer, has the ability to (i) make capital distributions of up to 15% of its total statutory capital per the previous year’s statutory financial statements or (ii) make dividend payments of up to 25% of its total statutory capital and surplus per the previous year’s statutory financial statements, without prior approval of Bermuda regulatory authorities.
The discounted cash flow analysis used to value the BAM Surplus Notes depends on key inputs, such as projections of future revenues and earnings for BAM, expected payments on the BAM Surplus Notes through maturity and a discount rate to reflect time value and related uncertainty of the repayment pattern.
The discounted cash flow analysis used to fair value the BAM Surplus Notes depends on key inputs, such as projections of future revenues and earnings for BAM, expected payments on the BAM Surplus Notes through maturity and a discount rate to reflect time value and related uncertainty of the repayment pattern.
For segment reporting, HG Global’s intercompany interest expense included within the HG Global segment is eliminated against the offsetting intercompany interest income included within Other Operations. (2) MSC collected are recorded directly to BAM’s equity, which is recorded as noncontrolling interest on White Mountains’s balance sheet.
For segment reporting, HG Global’s intercompany interest expense included within the HG Global segment is eliminated against the offsetting intercompany interest income included within Other Operations. (2) MSC collected are recorded directly to BAM’s equity, which is recorded as noncontrolling interests on White Mountains’s balance sheet.
The decrease in net investment income was driven primarily by a $12 million realization of carried interest for one of Kudu’s Participation Contracts in 2023, partially offset by amounts earned from $269 million in new deployments that Kudu made during 2023 and 2024.
The decrease in net investment income was driven primarily by a $12 million realization of carried interest for one of Kudu’s Participation Contracts in 2023, partially offset by amounts earned from new deployments that Kudu made during 2023 and 2024.
A discussion of White Mountains’s consolidated investment operations is included after the discussion of operations by segment. 50 Ark/WM Outrigger Ark is a specialty property and casualty insurance and reinsurance company that offers a wide range of niche insurance and reinsurance products, including property, specialty, marine & energy, casualty and accident & health.
A discussion of White Mountains’s consolidated investment operations is included after the discussion of operations by segment. Ark/WM Outrigger Ark is a specialty property and casualty insurance and reinsurance company that offers a wide range of niche insurance and reinsurance products, including property, specialty, marine & energy, casualty and accident & health.
(4) MSC collected are recorded directly to BAM’s equity, which was recorded as noncontrolling interest on White Mountains’s balance sheet through June 30, 2024. 58 December 31, 2023 Millions HG Global BAM Eliminations Total Direct written premiums $ — $ 58.6 $ — $ 58.6 Assumed written premiums 50.1 — (50.1) — Gross written premiums 50.1 58.6 (50.1) 58.6 Ceded written premiums — (50.1) 50.1 — Net written premiums $ 50.1 $ 8.5 $ — $ 58.6 Earned insurance and reinsurance premiums $ 26.0 $ 5.2 $ — $ 31.2 Net investment income 17.1 14.6 — 31.7 Net realized and unrealized investment gains (losses) 13.6 13.0 — 26.6 Interest income from BAM Surplus Notes 26.2 — (26.2) — Other revenues — 2.9 — 2.9 Total revenues 82.9 35.7 (26.2) 92.4 Insurance and reinsurance acquisition expenses 7.4 1.2 — 8.6 General and administrative expenses 2.8 66.1 — 68.9 Interest expense (1) 17.0 — — 17.0 Interest expense from BAM Surplus Notes — 26.2 (26.2) — Total expenses 27.2 93.5 (26.2) 94.5 Pre-tax income (loss) $ 55.7 $ (57.8) $ — $ (2.1) Supplemental information: MSC collected (2) $ — $ 72.8 $ — $ 72.8 (1) Amount includes $0.5 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements.
(5) MSC collected are recorded directly to BAM’s equity, which was recorded as noncontrolling interests on White Mountains’s balance sheet through June 30, 2024. 62 December 31, 2023 Millions HG Global BAM Eliminations Total Direct written premiums $ — $ 58.6 $ — $ 58.6 Assumed written premiums 50.1 — (50.1) — Gross written premiums 50.1 58.6 (50.1) 58.6 Ceded written premiums — (50.1) 50.1 — Net written premiums $ 50.1 $ 8.5 $ — $ 58.6 Earned insurance premiums $ 26.0 $ 5.2 $ — $ 31.2 Net investment income 17.1 14.6 — 31.7 Net realized and unrealized investment gains (losses) 13.6 13.0 — 26.6 Interest income from BAM Surplus Notes 26.2 — (26.2) — Other revenues — 2.9 — 2.9 Total revenues 82.9 35.7 (26.2) 92.4 Acquisition expenses 7.4 1.2 — 8.6 General and administrative expenses 2.8 66.1 — 68.9 Interest expense (1) 17.0 — — 17.0 Interest expense from BAM Surplus Notes — 26.2 (26.2) — Total expenses 27.2 93.5 (26.2) 94.5 Pre-tax income (loss) $ 55.7 $ (57.8) $ — $ (2.1) Supplemental information: MSC collected (2) $ — $ 72.8 $ — $ 72.8 (1) Amount includes $0.5 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements.
White Mountains’s total consolidated portfolio return on invested assets, both including and excluding White Mountains’s investment in MediaAlpha, was 11.4% in 2023. The total consolidated portfolio return included $27 million of net unrealized investment gains from White Mountains’s investment in MediaAlpha.
White Mountains’s total consolidated portfolio return on invested assets, both including and excluding White Mountains’s investment in MediaAlpha, was 11.4% in 2023. The total consolidated portfolio return included $27 million of unrealized investment gains from White Mountains’s investment in MediaAlpha.
The results in 2023 were driven primarily by net investment income and net unrealized investment gains as shorter-term interest rates declined marginally in the period. 69 Common Equity Securities, Investment in MediaAlpha and Other Long-Term Investments Results White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments totaled $3.0 billion and $2.8 billion as of December 31, 2024 and 2023, which represented 46% and 44% of total invested assets.
Results in 2023 were driven primarily by net investment income and net unrealized investment gains as shorter-term interest rates declined marginally in the period. 75 Common Equity Securities, Investment in MediaAlpha and Other Long-Term Investments Results White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments totaled $3.0 billion and $2.8 billion as of December 31, 2024 and 2023, which represented 46% and 44% of total invested assets.
MGA pre-tax income (loss) and MGA net income (loss) are non-GAAP financial measures that exclude the results of the Bamboo Captive, which is consolidated under GAAP, from Bamboo’s consolidated GAAP pre-tax income (loss) and net income (loss).
MGA pre-tax income (loss) and MGA net income (loss) are non-GAAP financial measures that exclude the results of the Bamboo Captive, which is consolidated by Bamboo MGA under GAAP, from Bamboo’s consolidated GAAP pre-tax income (loss) and net income (loss).
This is because ranges are developed based on known events as of the valuation date, whereas the ultimate disposition of losses is subject to the outcome of events and circumstances that may be unknown as of the valuation date. 86 Sensitivity Analysis Below is a discussion of possible variations from current estimates of loss and LAE reserves due to changes in certain key assumptions.
This is because ranges are developed based on known events as of the valuation date, whereas the ultimate disposition of losses is subject to the outcome of events and circumstances that may be unknown as of the valuation date. 91 Sensitivity Analysis Below is a discussion of possible variations from current estimates of loss and LAE reserves due to changes in certain key assumptions.
The estimated payments reflected in the table are based on current accrual factors (including performance relative to targets and common share price) and assume that all outstanding balances were 100% vested as of December 31, 2024. There are no provisions within White Mountains’s operating lease agreements that would trigger acceleration of future lease payments.
The estimated payments reflected in the table are based on current accrual factors (including performance relative to targets and common share price) and assume that all outstanding balances were 100% vested as of December 31, 2025. There are no provisions within White Mountains’s operating lease agreements that would trigger acceleration of future lease payments.
The difference between White Mountains’s effective tax rate and the current U.S. statutory rate of 21% was driven primarily by losses generated in jurisdictions with lower tax rates than the United States, a full valuation allowance on net deferred tax assets in certain U.S. operations (consisting of Other Operations and BAM), withholding taxes and state income taxes. IV.
The difference between White Mountains’s effective tax rate and the current U.S. statutory rate of 21% was driven primarily by income generated in jurisdictions with lower tax rates than the United States, a full valuation allowance on net deferred tax assets in certain U.S. operations (consisting of Other Operations and BAM), withholding taxes and state income taxes.
HG Global As of December 31, 2024, HG Global had $619 million face value of preferred shares outstanding, of which White Mountains owned 96.9%. Holders of the HG Global preferred shares are entitled to receive cumulative dividends at a fixed annual rate of 6.0% on a quarterly basis, payable when and if declared by HG Global.
HG Global As of December 31, 2025, HG Global had $619 million face value of preferred shares outstanding, of which White Mountains owned 96.9%. Holders of the HG Global preferred shares are entitled to receive cumulative dividends at a fixed annual rate of 6.0% on a quarterly basis, payable when and if declared by HG Global.
For segment reporting, these amounts are included within the HG Global segment and are eliminated against the offsetting receivables included within Other Operations. 63 Kudu Kudu provides capital solutions for boutique asset and wealth managers for a variety of purposes including generational ownership transfers, management buyouts, acquisition and growth finance and legacy partner liquidity.
For segment reporting, these amounts are included within the HG Global segment and are eliminated against the offsetting receivables included within Other Operations. 66 Kudu Kudu provides capital solutions for boutique asset and wealth managers for a variety of purposes, including generational ownership transfers, management buyouts, acquisition and growth finance and legacy partner liquidity.
WM Outrigger Re does not require regulatory approval to pay dividends; however, its dividend capacity is limited to amounts held outside of the collateral trust pursuant to its reinsurance agreement with GAIL. As of December 31, 2024, WM Outrigger Re had less than $1 million of net unrestricted cash held outside the collateral trust.
WM Outrigger Re does not require regulatory approval to pay dividends; however, its dividend capacity is limited to amounts held outside of the collateral trust pursuant to its reinsurance agreement with GAIL. As of December 31, 2025, WM Outrigger Re had less than $1 million of net unrestricted cash held outside the collateral trust.
In determining fair value, White Mountains considers factors for each of Kudu’s investees, such as performance of products and vehicles, expected asset growth rates, new fund launches, fee rates by product, capacity constraints, operating cash flows and other qualitative factors, including the assessment of key personnel.
In determining fair value, White Mountains considers factors for each of Kudu’s managers, such as performance of products and vehicles, expected asset growth rates, new fund launches, fee rates by product, capacity constraints, operating cash flows and other qualitative factors, including the assessment of key personnel.
See Note 5 — “Loss and Loss Adjustment Expense Reserves” on page F- 34 for a description of Ark’s loss and LAE reserves and actuarial methods. Ark performs an actuarial review of its recorded loss and LAE reserves each quarter, using several generally accepted actuarial methods to evaluate its loss reserves, each of which has its own strengths and weaknesses.
See Note 5 — “Loss and Loss Adjustment Expense Reserves” on page F- 36 for a description of Ark’s loss and LAE reserves and actuarial methods. Ark performs an actuarial review of its recorded loss and LAE reserves each quarter, using several generally accepted actuarial methods to evaluate its loss reserves, each of which has its own strengths and weaknesses.
The following tables present the components of pre-tax income (loss) included in the HG Global segment for the years ended December 31, 2024, 2023 and 2022. The HG Global segment consists of HG Global, which includes HG Re and its other wholly-owned subsidiaries, and, prior to its deconsolidation on July 1, 2024, BAM.
The following tables present the components of pre-tax income (loss) included in the HG Global segment for the years ended December 31, 2025, 2024 and 2023. The HG Global segment consists of HG Global, which includes HG Re and its other wholly-owned subsidiaries, and, prior to its deconsolidation on July 1, 2024, BAM.
MGA adjusted EBITDA is a non-GAAP financial measure that excludes certain other items in GAAP net income (loss) in addition to those added back to calculate MGA EBITDA. The items relate to (i) non-cash equity-based compensation expense, (ii) software implementation expenses and (iii) restructuring expenses.
MGA adjusted EBITDA is a non-GAAP financial measure that excludes certain other items in GAAP net income (loss) in addition to those added back to calculate MGA EBITDA. The items relate to (i) non-cash equity-based compensation expense, (ii) software implementation expenses, (iii) restructuring expenses and (iv) transaction expenses.
HG Global’s total gross pricing was 177 basis points in 2024, compared to 213 basis points in 2023. Pricing in the primary market decreased to 140 basis points in 2024 compared to 164 basis points in 2023, due to narrower municipal bond spreads and an increase in the volume of large, higher-credit issuances insured by BAM.
HG Global’s total gross pricing was 177 basis points in 2024 compared to 213 basis points in 2023. Pricing in the primary market decreased to 140 basis points in 2024 compared to 164 basis points in 2023, due to tighter municipal bond spreads and an increase in the volume of large, higher-credit issuances insured by BAM.
See Note 3 — “Investment Securities ” on page F- 21 . White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 10.0% in 2024, which included $38 million of net realized and unrealized investment gains from White Mountains’s investment in MediaAlpha.
See Note 3 — “Investment Securities ” on page F- 23 . White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 10.0% in 2024, which included $38 million of net realized and unrealized investment gains from White Mountains’s investment in MediaAlpha.
Share Repurchase Programs The Company’s Board of Directors has authorized it to repurchase its common shares from time to time, subject to market conditions. Shares may be repurchased on the open market or through privately negotiated transactions. The repurchase authorizations do not have a stated expiration date.
Share Repurchase Programs The Company’s Board of Directors has authorized the Company to repurchase its common shares from time to time, subject to market conditions. Shares may be repurchased on the open market or through privately negotiated transactions. The repurchase authorizations do not have a stated expiration date.
For segment reporting, HG Global’s intercompany other revenues included within the HG Global segment are eliminated against the offsetting intercompany expense included within Other Operations. (3) Amount includes $1.0 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements.
(3) Amount includes $0.5 of intercompany revenues that are eliminated in White Mountains’s consolidated financial statements. For segment reporting, HG Global’s intercompany revenues included within the HG Global segment are eliminated against the offsetting intercompany expense included within Other Operations (4) Amount includes $1.0 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements.
White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Bamboo’s performance. See page 66 for the reconciliation of Bamboo’s consolidated GAAP net income (loss) to MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA.
White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Bamboo’s performance. See page 69 for the reconciliation of Bamboo’s consolidated GAAP net income (loss) to MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA.
As a result of the deconsolidation, the BAM Surplus Notes are recorded at fair value, which resulted in the reversal of a $5 million deferred tax liability related to the economic transition adjustment, generating a $5 million tax benefit in the third quarter of 2024.
As a result of the deconsolidation, the BAM Surplus Notes are recorded at fair value, which resulted in the reversal of a $5 million deferred tax liability related to the economic transition adjustment, generating a $5 million deferred tax benefit in 2024.
The bottom section of the table is supplementary information about the average historical claims duration as of December 31, 2024. It shows the weighted average annual percentage payout of incurred loss and LAE by accident year as of each age.
The bottom section of the table is supplementary information about the average historical claims duration as of December 31, 2025. It shows the weighted average annual percentage payout of incurred loss and LAE by accident year as of each age.
As of December 31, 2024, White Mountains concluded that an after-tax discount rate of 24% and a terminal revenue growth rate of 4% were appropriate for the valuation of its investment in PassportCard/DavidShield.
As of December 31, 2025, White Mountains concluded that an after-tax discount rate of 24% and a terminal revenue growth rate of 4% were appropriate for the valuation of its investment in PassportCard/DavidShield.
For example, the first column is calculated as the incremental paid loss and LAE in the first calendar year for each given accident year (e.g., calendar year 2024 for accident year 2024, calendar year 2023 for accident year 2023) divided by the cumulative incurred loss and LAE as of December 31, 2024 for that accident year.
For example, the first column is calculated as the incremental paid loss and LAE in the first calendar year for each given accident year (e.g., calendar year 2025 for accident year 2025, calendar year 2024 for accident year 2024) divided by the cumulative incurred loss and LAE as of December 31, 2025 for that accident year.
To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries, (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets and (iii) not have a consolidated Bermuda affiliate or Bermuda permanent establishment directly or indirectly owned by a parent entity that is subject to the Income Inclusion Rule of Pillar Two in any jurisdiction.
To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries, (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets and (iii) not have a consolidated Bermuda affiliate or Bermuda permanent establishment directly or indirectly owned by a parent entity that is subject to the Pillar Two IIR in any jurisdiction.
LIQUIDITY AND CAPITAL RESOURCES Operating Cash and Short-term Investments Holding Company Level The primary sources of cash for the Company and certain of its intermediate holding companies are expected to be distributions from its insurance, reinsurance and other operating subsidiaries, net investment income, proceeds from sales, repayments and maturities of investments, capital raising activities and, from time to time, proceeds from sales of operating subsidiaries.
LIQUIDITY AND CAPITAL RESOURCES Operating Cash and Short-term Investments Holding Company Level The primary sources of cash for the Company and certain of its intermediate holding companies are expected to be distributions from its insurance, reinsurance and other operating subsidiaries, net investment income, proceeds from sales, repayments and maturities of investments, borrowings from credit facilities, capital raising activities and, from time to time, proceeds from sales of operating subsidiaries.
Range of Reserves The following table shows the recorded loss and LAE reserves and the high and low ends of Ark’s range of reasonable loss and LAE reserve estimates, net of reinsurance recoverables on unpaid losses, as of December 31, 2024.
Range of Reserves The following table shows the recorded loss and LAE reserves and the high and low ends of Ark’s range of reasonable loss and LAE reserve estimates, net of reinsurance recoverables on unpaid losses, as of December 31, 2025.
Operating Subsidiary Level The primary sources of cash for White Mountains’s insurance, reinsurance and other operating subsidiaries are expected to be premium and fee collections, commissions, net investment income, proceeds from sales, repayments and maturities of investments, contributions from holding companies and capital raising activities.
Operating Subsidiary Level The primary sources of cash for White Mountains’s insurance, reinsurance and other operating subsidiaries are expected to be premium and fee collections, commissions, net investment income, proceeds from sales, repayments and maturities of investments, contributions from holding companies, borrowings from credit facilities and capital raising activities.
Also included in this section is a calculation of the loss and LAE reserves as of December 31, 2024, which is then included in the reconciliation to the consolidated balance sheet presented above.
Also included in this section is a calculation of the loss and LAE reserves as of December 31, 2025, which is then included in the reconciliation to the consolidated balance sheet presented above.
Gross Investment Returns and Benchmark Returns The following table presents the pre-tax time-weighted investment returns for White Mountains’s consolidated portfolio for the years ended December 31, 2024, 2023 and 2022: Year Ended December 31, 2024 2023 2022 Fixed income investments 4.3 % 5.8 % (4.8) % Bloomberg U.S.
Gross Investment Returns and Benchmark Returns The following table presents the pre-tax time-weighted investment returns for White Mountains’s consolidated portfolio for the years ended December 31, 2025, 2024 and 2023: Year Ended December 31, 2025 2024 2023 Fixed income investments 5.9 % 4.3 % 5.8 % Bloomberg U.S.
However, whether actual results and developments will conform to its expectations and predictions is subject to risks and uncertainties that could cause actual results to differ materially from expectations, including: • the risks associated with Item 1A of this Report on Form 10-K; • claims arising from catastrophic events, such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis, severe weather, public health crises, terrorist attacks, war and war-like actions, explosions, infrastructure failures or cyber-attacks; • recorded loss reserves subsequently proving to have been inadequate; • the market value of White Mountains’s investment in MediaAlpha; • the trends and uncertainties from the COVID-19 pandemic, including judicial interpretations on the extent of insurance coverage provided by insurers for COVID-19 pandemic related claims; • business opportunities (or lack thereof) that may be presented to it and pursued; • actions taken by rating agencies, such as financial strength or credit ratings downgrades or placing ratings on negative watch; • the continued availability of capital and financing; • the continued availability of fronting and reinsurance capacity; • deterioration of general economic, market or business conditions, including due to outbreaks of contagious disease (including the COVID-19 pandemic) and corresponding mitigation efforts; • competitive forces, including the conduct of other insurers; • changes in domestic or foreign laws or regulations, or their interpretation, applicable to White Mountains, its competitors or its customers; and • other factors, most of which are beyond White Mountains’s control.
However, whether actual results and developments will conform to its expectations and predictions is subject to risks and uncertainties that could cause actual results to differ materially from expectations, including: • the risks associated with Item 1A of this Report on Form 10-K; • claims arising from catastrophic events, such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis, severe weather, public health crises, terrorist attacks, war and war-like actions, explosions, infrastructure failures or cyber attacks; • recorded loss reserves subsequently proving to have been inadequate; • the market value of White Mountains’s investment in MediaAlpha; • business opportunities (or lack thereof) that may be presented to it and pursued; • actions taken by rating agencies, such as financial strength or credit ratings downgrades or placing ratings on negative watch; • the continued availability of capital and financing; • the continued availability of fronting and reinsurance capacity; • deterioration of general economic, market or business conditions, including due to outbreaks of contagious disease and corresponding mitigation efforts; • competitive forces, including the conduct of other insurers; • changes in domestic or foreign laws or regulations, or their interpretation, applicable to White Mountains, its competitors or its customers; and • other factors, most of which are beyond White Mountains’s control.
Significant intercompany transactions among White Mountains’s segments have been eliminated herein. White Mountains’s segment information is presented in Note 15 — “Segment Information” on page F- 65 .
Significant intercompany transactions among White Mountains’s segments have been eliminated herein. White Mountains’s segment information is presented in Note 15 — “Segment Information” on page F- 70 .
Valuation of assets and liabilities measured at fair value require management to make estimates and apply judgment to matters that may carry a significant degree of uncertainty. In determining its estimates of fair value, White Mountains uses a variety of valuation approaches and inputs.
The valuation of assets and liabilities measured at fair value requires management to make estimates and apply judgment to matters that may carry a significant degree of uncertainty. In determining its estimates of fair value, White Mountains uses a variety of valuation approaches and inputs.
Ark’s combined ratio was 83% in 2024, compared to 82% in 2023. Ark’s combined ratio included 13 points of catastrophe losses in 2024, driven primarily by Hurricanes Milton, Helene, Debby and Beryl, compared to two points of catastrophe losses in 2023, driven primarily by Hurricanes Otis and Idalia as well as the Maui wildfires.
Ark’s combined ratio included 13 points of catastrophe losses in 2024, driven primarily by Hurricanes Milton, Helene, Debby and Beryl, compared to two points of catastrophe losses in 2023, driven primarily by Hurricanes Otis and Idalia as well as the Maui wildfires.
White Mountains’s portfolio of common equity securities and other long-term investments returned 9.4% in 2024. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 18.5% in 2023, which included $27 million of net unrealized investment gains from MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 19.0% in 2023.
White Mountains’s portfolio of common equity securities and other long-term investments returned 9.4% in 2024. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 18.5% in 2023, which included $27 million of unrealized investment gains from White Mountains’s investment in MediaAlpha.
As of December 31, 2024, Ark and its intermediate holding companies had $6 million of net unrestricted cash and short-term investments outside of its regulated and unregulated insurance and reinsurance operating subsidiaries. WM Outrigger Re is a special purpose insurer subject to regulation and supervision by the BMA.
As of December 31, 2025, Ark and its intermediate holding companies had $9 million of net unrestricted cash and short-term investments outside of its regulated and unregulated insurance and reinsurance operating subsidiaries. WM Outrigger Re is a special purpose insurer subject to regulation and supervision by the BMA.
The middle section of the table presents cumulative paid loss and LAE for each of the previous 10 accident years as of each of the previous 10 year-end evaluations.
The middle section of the table presents cumulative paid loss and LAE for each of the previous ten accident years as of each of the previous ten year-end evaluations.
SUMMARY OF OPERATIONS BY SEGMENT As of December 31, 2024, White Mountains conducted its operations through four reportable segments: (1) Ark/WM Outrigger, (2) HG Global, (3) Kudu and (4) Bamboo, with our remaining operating businesses, holding companies and other assets included in Other Operations.
SUMMARY OF OPERATIONS BY SEGMENT As of December 31, 2025, White Mountains conducted its operations through four reportable segments: (1) Ark/WM Outrigger, (2) HG Global, (3) Kudu and (4) Distinguished, with our remaining operating businesses, holding companies and other assets included in Other Operations.
White Mountains’s portfolio of common equity securities consists of international listed equity funds, primarily held at Ark, and passive ETFs. White Mountains’s ETFs seek to provide investment results generally corresponding to the performance of the S&P 500 Index. White Mountains’s portfolio of common equity securities was $650 million and $538 million as of December 31, 2024 and 2023.
White Mountains’s portfolio of common equity securities generally consists of international listed equity funds, primarily held at Ark, and passive ETFs. White Mountains’s ETFs seek to provide investment results generally corresponding to the performance of the S&P 500 Index. White Mountains’s portfolio of common equity securities was $483 million and $650 million as of December 31, 2025 and 2024.
White Mountains’s fixed income portfolio includes fixed maturity and short-term investments held on deposit or as collateral. See Note 3 — “Investment Securities ” on page F- 21 . White Mountains’s fixed income portfolio returned 5.8% in 2023 compared to -4.8% in 2022, outperforming the Bloomberg U.S. Intermediate Aggregate Index returns of 5.2% and -9.5% for the comparable periods.
White Mountains’s fixed income portfolio includes fixed maturity and short-term investments held on deposit or as collateral. See Note 3 — “Investment Securities ” on page F- 23 . White Mountains’s fixed income portfolio returned 4.3% in 2024 compared to 5.8% in 2023, outperforming the Bloomberg U.S. Intermediate Aggregate Index returns of 2.5% and 5.2% for the comparable periods.
The following table presents Bamboo’s managed premiums for the years ended December 31, 2024, 2023 and 2022, which includes periods prior to White Mountains’s ownership of Bamboo. White Mountains believes this information is useful in understanding the overall growth in Bamboo’s premium base.
The following table presents Bamboo’s managed premiums for the years ended December 31, 2025, 2024 and 2023, which includes periods prior to White Mountains’s ownership of Bamboo and subsequent to the deconsolidation of Bamboo. White Mountains believes this information is useful in understanding the overall growth in Bamboo’s premium base.
White Mountains also has future binding commitments to fund certain other long-term investments. These commitments, which totaled approximately $94 million as of December 31, 2024, do not have fixed funding dates and are therefore excluded from the table above.
White Mountains also has future binding commitments to fund certain other long-term investments. These commitments, which totaled approximately $176 million as of December 31, 2025, do not have fixed funding dates and are therefore excluded from the table above.
HG Global’s results included net realized and unrealized investment gains (losses) on its fixed income portfolio of $(6) million in 2024 compared to $14 million in 2023, driven by interest rate movements in each period. HG Global’s results included interest income on the BAM Surplus Notes of $29 million in 2024 compared to $26 million in 2023.
HG Global’s results included net realized and unrealized investment gains (losses) on its fixed income portfolio of $(6) million in 2024 compared to $14 million in 2023, driven by movements in interest rates. HG Global’s results included interest income on the BAM Surplus Notes of $29 million in 2024 compared to $26 million in 2023.
(2) Includes $35.8 of non-cash contributions to (proceeds from) Participation Contracts for the year ended December 31, 2023. (3) Includes $28.1 of proceeds receivable from Participation Contracts sold during the year ended December 31, 2024 (4) Includes net realized and unrealized investment gains (losses) recognized from Participation Contracts beginning in the quarter a contract is classified as pending sale.
(2) Includes $6.6 of non-cash contributions to (proceeds from) Participation Contracts for the year ended December 31, 2025. (3) Includes $28.1 of proceeds receivable from Participation Contracts sold during the year ended December 31, 2024. (4) Includes net realized and unrealized investment gains (losses) recognized from Participation Contracts beginning in the quarter a contract is classified as pending sale.
The expected future cash flows are based on management judgment, considering current performance, budgets and projected future results. The discount rate reflects the weighted average cost of capital, considering comparable public company data and adjusted for risks specific to the business and industry.
The expected future cash flows are based on management judgment, considering current performance, budgets and projected future results. The discount rates reflect the weighted average cost of capital, considering comparable public company data and adjusted for risks specific to the business and industry.
The following table presents the reconciliation from Bamboo’s consolidated GAAP pre-tax income (loss) to MGA pre-tax income (loss): Millions Year Ended December 31, 2024 Bamboo’s consolidated GAAP pre-tax income (loss) $ 32.7 Remove pre-tax (income) loss, Bamboo Captive (1.0) MGA pre-tax income (loss) $ 31.7 80 MGA EBITDA is a non-GAAP financial measure that adds back interest expense on debt, income tax (expense) benefit, depreciation and amortization of other intangible assets to MGA net income (loss).
The following table presents the reconciliation from Bamboo’s consolidated GAAP pre-tax income (loss) to MGA pre-tax income (loss): Millions January 1, 2025 - December 5, 2025 Year Ended December 31, 2024 Bamboo’s consolidated GAAP pre-tax income (loss) $ 40.1 $ 32.7 Remove pre-tax (income) loss, Bamboo Captive 1.0 (1.0) MGA pre-tax income (loss) $ 41.1 $ 31.7 MGA EBITDA is a non-GAAP financial measure that adds back interest expense on debt, income tax (expense) benefit, depreciation and amortization of other intangible assets to MGA net income (loss).
White Mountains’s Other Operations reported $9 million of pre-tax income in 2024 related to the Bamboo CRV, which incepted on April 1, 2024. The Bamboo CRV’s results included $33 million of earned premiums, $12 million of loss and loss adjustment expenses and $12 million of acquisition expenses.
White Mountains’s Other Operations reported $9 million of pre-tax income in 2024 related to the Bamboo CRV that incepted on April 1, 2024. The Bamboo CRV’s results included earned premiums of $33 million, loss and LAE of $12 million and acquisition expenses of $12 million.
As of December 31, 2024, the asset and wealth management firms have combined assets under management (“AUM”) of approximately $125 billion, spanning a range of asset classes, including real estate, wealth management, hedge funds, private equity and alternative credit strategies.
As of December 31, 2025, the asset and wealth management firms have combined assets under management (“AUM”) of approximately $153 billion, spanning a range of asset classes, including real estate, real assets, wealth management, hedge funds, private equity and alternative credit strategies.
For example, a hypothetical increase in inflation rates by 4% per annum would increase the recorded loss and LAE reserves, net of reinsurance recoverables on unpaid losses, for the casualty reserving lines of business by approximately $16 million, or approximately 7% of the recorded casualty loss and LAE reserves of $245 million. • Catastrophe losses : The years 2017 through 2024 have been active for major loss events, including natural catastrophes.
For example, a hypothetical increase in inflation rates by 4% per annum would increase the recorded loss and LAE reserves, net of reinsurance recoverables on unpaid losses, for the casualty reserving lines of business by approximately $20 million, or approximately 7% of the recorded casualty loss and LAE reserves of $288 million. • Catastrophe losses : The years 2017 through 2025 have been active for major loss events, including natural catastrophes.
The discount rate considers comparably-rated companies and instruments, adjusted for risks specific to BAM and the BAM Surplus Notes. As of December 31, 2024, White Mountains concluded that a discount rate of 8.1% was appropriate for the valuation of the BAM Surplus Notes.
The discount rate considers comparably-rated companies and instruments, adjusted for risks specific to BAM and the BAM Surplus Notes. As of December 31, 2025, White Mountains concluded that a discount rate of 8.05% was appropriate for the valuation of the BAM Surplus Notes.
TRANSACTIONS WITH RELATED PERSONS White Mountains does not have any transactions with related persons to report as of December 31, 2024. NON-GAAP FINANCIAL MEASURES This report includes 11 non-GAAP financial measures that have been reconciled from their most comparable GAAP financial measures.
TRANSACTIONS WITH RELATED PERSONS White Mountains does not have any transactions with related persons to report as of December 31, 2025. NON-GAAP FINANCIAL MEASURES This report includes 12 non-GAAP financial measures that have been reconciled from their most comparable GAAP financial measures.
The total unpaid loss and LAE reserves as of December 31, 2024 is calculated as the cumulative incurred loss and LAE from the top section less the cumulative paid loss and LAE from the middle section, plus any outstanding liabilities from accident years prior to 2014.
The total unpaid loss and LAE reserves as of December 31, 2025 is calculated as the cumulative incurred loss and LAE from the top section less the cumulative paid loss and LAE from the middle section, plus any outstanding liabilities from accident years prior to 2015.
The inputs to each discounted cash flow analysis vary depending on the nature of each of Kudu’s investees. As of December 31, 2024, White Mountains concluded that pre-tax discount rates in the range of 17% to 25% and terminal cash flow exit multiples in the range of 7 to 22 times were appropriate for the valuations of Kudu’s Participation Contracts.
The inputs to each discounted cash flow analysis vary depending on the nature of each of Kudu’s managers. As of December 31, 2025, White Mountains concluded that pre-tax discount rates in the range of 16% to 25% and terminal cash flow exit multiples in the range of 7 to 22 times were appropriate for the valuations of Kudu’s Participation Contracts.
HG Global has two primary sources of cash flows: (i) interest payments on the BAM Surplus Notes that are made outside the Collateral Trusts and (ii) releases of excess balances from the Collateral Trusts. During 2024, HG Global received cash payments of principal and interest on the BAM Surplus Notes of $30 million.
HG Global has two primary sources of cash flows: (i) interest payments on the BAM Surplus Notes that are made outside the Collateral Trusts and (ii) releases of excess balances from the Collateral Trusts. During 2025, HG Global received cash payments of principal and interest on the BAM Surplus Notes totaling $35 million.
December 31, 2024 Millions HG Global BAM (1) Eliminations Total Direct written premiums $ — $ 24.1 $ — $ 24.1 Assumed written premiums 52.4 — (20.5) 31.9 Gross written premiums 52.4 24.1 (20.5) 56.0 Ceded written premiums — (20.5) 20.5 — Net written premiums $ 52.4 $ 3.6 $ — $ 56.0 Earned insurance and reinsurance premiums $ 28.9 $ 2.8 $ — $ 31.7 Net investment income 23.4 8.8 — 32.2 Net realized and unrealized investment gains (losses) (6.4) (5.1) — (11.5) Interest income from BAM Surplus Notes 29.0 — (13.2) 15.8 Change in fair value of BAM Surplus Notes .5 — — .5 Unrealized loss on deconsolidation of BAM (114.5) — — (114.5) Other revenues (2) .6 1.1 — 1.7 Total revenues (38.5) 7.6 (13.2) (44.1) Acquisition expenses 7.8 .4 — 8.2 General and administrative expenses 2.2 33.5 — 35.7 Interest expense (3) 17.7 — — 17.7 Interest expense from BAM Surplus Notes — 13.2 (13.2) — Total expenses 27.7 47.1 (13.2) 61.6 Pre-tax income (loss) $ (66.2) $ (39.5) $ — $ (105.7) Supplemental information: MSC collected (4) $ — $ 26.0 $ — $ 26.0 (1) Effective July 1, 2024, White Mountains no longer consolidates BAM.
For segment reporting, HG Global’s intercompany revenues included within the HG Global segment are eliminated against the offsetting intercompany expense included within Other Operations. 61 December 31, 2024 Millions HG Global BAM (1) Eliminations Total Direct written premiums $ — $ 24.1 $ — $ 24.1 Assumed written premiums 52.4 — (20.5) 31.9 Gross written premiums 52.4 24.1 (20.5) 56.0 Ceded written premiums — (20.5) 20.5 — Net written premiums $ 52.4 $ 3.6 $ — $ 56.0 Earned insurance premiums $ 28.9 $ 2.8 $ — $ 31.7 Net investment income 23.4 8.8 — 32.2 Net realized and unrealized investment gains (losses) (6.4) (5.1) — (11.5) Interest income from BAM Surplus Notes 29.0 — (13.2) 15.8 Change in fair value of BAM Surplus Notes .5 — — .5 Unrealized loss on deconsolidation of BAM (2) (114.5) — — (114.5) Other revenues (3) .6 1.1 — 1.7 Total revenues (38.5) 7.6 (13.2) (44.1) Acquisition expenses 7.8 .4 — 8.2 General and administrative expenses 2.2 33.5 — 35.7 Interest expense (4) 17.7 — — 17.7 Interest expense from BAM Surplus Notes — 13.2 (13.2) — Total expenses 27.7 47.1 (13.2) 61.6 Pre-tax income (loss) $ (66.2) $ (39.5) $ — $ (105.7) Supplemental information: MSC collected (5) $ — $ 26.0 $ — $ 26.0 (1) Effective July 1, 2024, White Mountains no longer consolidates BAM.
Accordingly, GAIL will have the ability to pay a dividend of up to $337 million during 2025, which is equal to 25% of its statutory capital and surplus of $1,347 million as of December 31, 2024, subject to meeting all appropriate liquidity and solvency requirements and the filing of its December 31, 2024 statutory financial statements.
Accordingly, GAIL will have the ability to pay a dividend of up to $425 million during 2026, which is equal to 25% of its statutory capital and surplus of $1,700 million as of December 31, 2025, subject to meeting all appropriate liquidity and solvency requirements and the filing of its December 31, 2025 statutory financial statements.
Investment returns for 2023 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, net realized and unrealized investment gains from private equity funds, hedge funds and unconsolidated entities, as well as unrealized gains from ILS funds.
Returns for 2025 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, as well as net investment income and net realized and unrealized investment gains from certain unconsolidated entities, private equity funds and hedge funds.
The following table presents common shares repurchased by the Company as well as the average price per share as a percent of December 31, 2024 GAAP book value per share, adjusted book value per share and market value per share.
The following table presents common shares repurchased by the Company as well as the average price per share as a percent of December 31, 2025 book value per share and market value per share.
As of December 31, 2024, White Mountains may repurchase an additional 301,014 shares under these Board authorizations. In addition, from time to time White Mountains has also repurchased its common shares through self-tender offers that were separately authorized by its Board of Directors.
As of December 31, 2025, White Mountains may repurchase an additional 269,594 shares under these Board authorizations. In addition, from time to time White Mountains has also repurchased its common shares through self-tender offers that were separately authorized by its Board of Directors.
As time has passed, the emerging claims information for major loss events has been better than expected. As of December 31, 2024, Ark has recorded $158 million of loss and LAE reserves, net of reinsurance recoverables on unpaid losses, for major loss events, of which $135 million is held as IBNR reserves.
As time has passed, the emerging claims information for major loss events has been better than expected. As of December 31, 2025, Ark has recorded $230 million of loss and LAE reserves, net of reinsurance recoverables on unpaid losses, for major loss events, of which $171 million is held as IBNR reserves.
Ark Loss and LAE Development See Note 5 — “Loss and Loss Adjustment Expense Reserves” on page F- 34 for prior year loss and LAE development discussions for the year ended December 31, 2024.
Ark Loss and LAE Development See Note 5 — “Loss and Loss Adjustment Expense Reserves” on page F- 36 for prior year loss and LAE development discussions for the year ended December 31, 2025.
Goodwill and Other Intangible Assets As of December 31, 2024, goodwill and other intangible assets recognized in connection with business and asset acquisitions totaled $720 million, of which $530 million was attributable to White Mountains’s common shareholders. Under the acquisition method, White Mountains recognizes and measures the assets acquired, including other intangible assets, at their acquisition date fair values.
Goodwill and Other Intangible Assets As of December 31, 2025, goodwill and other intangible assets recognized in connection with business and asset acquisitions totaled $1,020 million, of which $642 million was attributable to White Mountains’s common shareholders. Under the acquisition method, White Mountains recognizes and measures the assets acquired, including other intangible assets, at their acquisition date fair values.
Risk Factors, “ We may be subject to greater volatility from the BAM Surplus Notes, as the valuation of the BAM Surplus Notes under the discounted cash flow analysis subsequent to deconsolidation could be more volatile, which could materially adversely affect our results of operations and financial condition.” on page 33 . 82 With a discounted cash flow analysis, small changes to key inputs may result in significant changes to fair value.
Risk Factors, “ We may be subject to volatility from the valuation of the BAM Surplus Notes, which could materially adversely affect our results of operations and financial condition.” on page 33 . With a discounted cash flow analysis, small changes to key inputs may result in significant changes to fair value.
The following table presents the components of GAAP net income (loss), EBITDA and adjusted EBITDA included in the Kudu segment for the years ended December 31, 2024, 2023 and 2022: Year Ended December 31, Millions 2024 2023 2022 Net investment income (1) $ 66.7 $ 71.0 $ 54.4 Net realized and unrealized investment gains (losses) 51.3 106.1 64.1 Other revenues .8 — — Total revenues 118.8 177.1 118.5 General and administrative expenses 15.4 19.4 14.7 Interest expense 22.1 21.2 15.0 Total expenses 37.5 40.6 29.7 GAAP pre-tax income (loss) 81.3 136.5 88.8 Income tax (expense) benefit (16.8) (31.9) (26.9) GAAP net income (loss) 64.5 104.6 61.9 Add back: Interest expense 22.1 21.2 15.0 Income tax expense (benefit) 16.8 31.9 26.9 General and administrative expenses – depreciation .1 .1 .1 Amortization of other intangible assets .3 .3 .3 EBITDA (2) 103.8 158.1 104.2 Exclude: Net realized and unrealized investment (gains) losses (51.3) (106.1) (64.1) Non-cash equity-based compensation expense .3 1.0 .2 Transaction expenses 1.7 3.5 1.5 Adjusted EBITDA (2) $ 54.5 $ 56.5 $ 41.8 (1) Net investment income includes revenues from participation contracts and income from short-term and other long-term investments.
The following table presents the components of GAAP net income (loss), EBITDA and adjusted EBITDA included in the Kudu segment for the years ended December 31, 2025, 2024 and 2023: Year Ended December 31, Millions 2025 2024 2023 Net investment income (1) $ 78.7 $ 66.7 $ 71.0 Net realized and unrealized investment gains (losses) 103.5 51.3 106.1 Other revenues 1.2 .8 — Total revenues 183.4 118.8 177.1 General and administrative expenses 17.9 15.4 19.4 Interest expense 25.9 22.1 21.2 Total expenses 43.8 37.5 40.6 GAAP pre-tax income (loss) 139.6 81.3 136.5 Income tax (expense) benefit (24.2) (16.8) (31.9) GAAP net income (loss) 115.4 64.5 104.6 Add back: Interest expense 25.9 22.1 21.2 Income tax expense (benefit) 24.2 16.8 31.9 General and administrative expenses – depreciation .2 .1 .1 Amortization of other intangible assets .3 .3 .3 EBITDA (2) 166.0 103.8 158.1 Exclude: Net realized and unrealized investment (gains) losses (103.5) (51.3) (106.1) Non-cash equity-based compensation expense .5 .3 1.0 Transaction expenses 1.9 1.7 3.5 Adjusted EBITDA (2) $ 64.9 $ 54.5 $ 56.5 (1) Net investment income includes revenues from Participation Contracts and income from short-term and other long-term investments.

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Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Market Risk — interest-rate, FX, commodity exposure

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Biggest changeThe following table presents the estimated pre-tax effects of hypothetical widening and tightening of credit spreads on White Mountains’s fixed maturity investments by asset class: December 31, 2024 Millions Fair Value Tighten 50 Tighten 25 Widen 25 Widen 50 U.S. government and agency obligations $ 462.1 $ — $ — $ — $ — Foreign government and agency obligations 21.5 — — — — Tighten 100 Tighten 50 Widen 50 Widen 100 Agency mortgage-backed securities 369.6 8.6 8.5 (11.0) (21.5) Other asset-backed securities 3.9 — — — (.1) Non-agency: mortgage-backed securities .4 — — — — Tighten 200 Tighten 100 Widen 100 Widen 200 Debt securities issued by corporations 1,414.2 23.6 22.4 (37.4) (74.8) Municipal obligations 3.2 .1 .1 (.2) (.3) Tighten 300 Tighten 200 Widen 200 Widen 300 Collateralized loan obligations 236.7 14.5 14.3 (22.7) (34.1) The magnitude of the fair value decrease in wider credit spread scenarios may be more significant than the fair value increase in comparable tighter credit spread scenarios.
Biggest changeThe following table presents the estimated pre-tax effects of hypothetical widening and tightening of credit spreads on White Mountains’s fixed maturity investments by asset class: December 31, 2025 Millions Fair Value Tighten 50 Tighten 25 Widen 25 Widen 50 U.S. government and agency obligations $ 460.3 $ — $ — $ — $ — Foreign government and agency obligations 32.5 — — — — Tighten 100 Tighten 50 Widen 50 Widen 100 Agency mortgage-backed securities 354.0 5.1 5.1 (10.3) (20.1) Other asset-backed securities 39.0 .6 .5 (.6) (1.2) Tighten 200 Tighten 100 Widen 100 Widen 200 Debt securities issued by corporations 1,537.7 15.8 15.4 (38.9) (77.8) Tighten 300 Tighten 200 Widen 200 Widen 300 Collateralized loan obligations 347.0 28.6 27.8 (38.7) (58.1) The magnitude of the fair value decrease in wider credit spread scenarios may be more significant than the fair value increase in comparable tighter credit spread scenarios.
See “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 82 for further discussion related to the valuation of Kudu’s Participation Contracts and White Mountains’s investment in PassportCard/DavidShield. BAM Surplus Notes The carrying value of the BAM Surplus Notes is based on management’s estimate of fair value as of the balance sheet date.
See “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 88 for further discussion related to the valuation of Kudu’s Participation Contracts and White Mountains’s investment in PassportCard/DavidShield. BAM Surplus Notes The carrying value of the BAM Surplus Notes is based on management’s estimate of fair value as of the balance sheet date.
See “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 82 for further discussion related to the valuation of the BAM Surplus Notes. Long-Term Obligations White Mountains carries its debt obligations at face value less unamortized debt issuance costs and original issue discount.
See “CRITICAL ACCOUNTING ESTIMATES — Fair Value Measurements” on page 88 for further discussion related to the valuation of the BAM Surplus Notes. Long-Term Obligations White Mountains carries its debt obligations at face value less unamortized debt issuance costs and original issue discount.
As of December 31, 2024, White Mountains’s fixed maturity investments are comprised primarily of debt securities issued by corporations, U.S. government and agency obligations, foreign government and agency obligations, municipal obligations, mortgage and asset-backed securities and collateralized loan obligations. Increases and decreases in prevailing interest rates generally translate into decreases and increases in fair values of fixed maturity investments, respectively.
As of December 31, 2025, White Mountains’s fixed maturity investments are comprised primarily of debt securities issued by corporations, U.S. government and agency obligations, foreign government and agency obligations, mortgage and asset-backed securities and collateralized loan obligations. Increases and decreases in prevailing interest rates generally translate into decreases and increases in fair values of fixed maturity investments, respectively.
Foreign Currency Exposure As of December 31, 2024, White Mountains had net assets of $192 million denominated in foreign currencies primarily related to Ark/WM Outrigger’s non-U.S. contracts, Kudu’s non-U.S. Participation Contracts and a private debt instrument, as well as certain other foreign consolidated and unconsolidated entities.
Foreign Currency Exposure As of December 31, 2025, White Mountains had net assets of $376 million denominated in foreign currencies primarily related to Ark/WM Outrigger’s non-U.S. contracts, Kudu’s non-U.S. Participation Contracts and a private debt instrument, as well as certain other foreign consolidated and unconsolidated entities.
White Mountains is required to disclose the fair value of certain financial instruments not carried at fair value, including the debt obligations. See Note 18 — “Fair Value of Financial Instruments” on page F- 72 for the fair value and carrying value of White Mountains’s debt obligations as of December 31, 2024 and 2023.
White Mountains is required to disclose the fair value of certain financial instruments not carried at fair value, including the debt obligations. See Note 18 — “Fair Value of Financial Instruments” on page F- 78 for the fair value and carrying value of White Mountains’s debt obligations as of December 31, 2025 and 2024.
See “ Summary of Investment Results - Foreign Currency Exposure” on page 72 for fair value of White Mountains’s foreign denominated net assets (liabilities) by segment as of December 31, 2024.
See “ Summary of Investment Results - Foreign Currency Exposure” on page 78 for fair value of White Mountains’s foreign denominated net assets (liabilities) by segment as of December 31, 2025.
Assuming a hypothetical 10% and 30% increase or decrease in the value of White Mountains’s common equity securities, investment in MediaAlpha and other long-term investments as of December 31, 2024, the carrying value of White Mountains’s common equity securities, investment in MediaAlpha and other long-term investments would increase or decrease by $300 million and $901 million on a pre-tax basis, respectively.
Assuming a hypothetical 10% and 30% increase or decrease in the value of White Mountains’s common equity securities, investment in MediaAlpha and other long-term investments as of December 31, 2025, the carrying value of White Mountains’s common equity securities, investment in MediaAlpha and other long-term investments would increase or decrease by $367 million and $1,102 million, respectively, on a pre-tax basis.
Assuming a hypothetical 10% and 30% increase or decrease in the value of the BAM Surplus Notes as of December 31, 2024, the carrying value of the BAM Surplus Notes would increase or decrease by $38 million and $115 million on a pre-tax basis, respectively.
Assuming a hypothetical 10% and 30% increase or decrease in the value of the BAM Surplus Notes as of December 31, 2025, the carrying value of the BAM Surplus Notes would increase or decrease by $34 million and $102 million, respectively, on a pre-tax basis.
The following table illustrates the pre-tax effect of a hypothetical 20% increase/decrease in the U.S. dollar exchange rate on the carrying value of net assets denominated in foreign currencies as of December 31, 2024: $ in Millions Carrying Value of Foreign Denominated Net Assets Hypothetical Change Hypothetical Pre-Tax Increase (Decrease) in Carrying Value Hypothetical Percentage Increase (Decrease) in Stockholders’ Equity $ 191.7 20% increase $ (38.3) (0.7) % 20% decrease $ 38.3 0.7 %
The following table illustrates the pre-tax effect of a hypothetical 20% increase (decrease) in the U.S. dollar exchange rate on the carrying value of net assets denominated in foreign currencies as of December 31, 2025: $ in Millions Carrying Value of Foreign Denominated Net Assets Hypothetical Change Hypothetical Pre-Tax Increase (Decrease) in Carrying Value Hypothetical Percentage Increase (Decrease) in Stockholders’ Equity $ 376.4 20% increase $ (75.3) (1.2) % 20% decrease $ 75.3 1.2 %
The following table presents the estimated effects of hypothetical increases and decreases in market interest rates on White Mountains’s fixed maturity investments: $ in Millions Fair Value at December 31, 2024 Assumed Change in Relevant Interest Rate Estimated Fair Value After Change in Interest Rate Pre-Tax Increase (Decrease) in Fair Value Fixed maturity investments $ 2,511.6 100 bps decrease $ 2,577.0 $ 65.4 50 bps decrease 2,544.5 32.9 50 bps increase 2,478.5 (33.1) 100 bps increase 2,445.6 (66.0) The magnitude of the fair value decrease in rising interest rate scenarios may be more significant than the fair value increase in comparable falling interest rate scenarios.
The following table presents the estimated effects of hypothetical increases and decreases in market interest rates on White Mountains’s fixed maturity investments: $ in Millions Fair Value at December 31, 2025 Assumed Change in Relevant Interest Rate Estimated Fair Value After Change in Interest Rate Pre-Tax Increase (Decrease) in Fair Value Fixed maturity investments $ 2,770.5 100 bps decrease $ 2,839.6 $ 69.1 50 bps decrease 2,805.3 34.8 50 bps increase 2,735.5 (35.0) 100 bps increase 2,700.5 (70.0) The magnitude of the fair value decrease in rising interest rate scenarios may be more significant than the fair value increase in comparable falling interest rate scenarios.

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