Biggest changeInterest Income Interest income consists of interest earned on cash, cash equivalents and investments. 80 Results of Operations Comparisons of the Years Ended December 31, 2022 and 2021 The following table summarizes our results of operations for the periods presented: Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Revenue: Product $ 8,557 $ 3,577 $ 4,980 139 % Service 913 500 413 83 % Related party 5,215 2,317 2,898 125 % Grant and other 808 223 585 262 % Total revenue 15,493 6,617 8,876 134 % Cost of revenue: Product 5,459 2,300 3,159 137 % Service 495 42 453 1079 % Related party 1,989 863 1,126 130 % Grant and other 457 — 457 100 % Total cost of revenue 8,400 3,205 5,195 162 % Gross profit 7,093 3,412 3,681 108 % Operating expenses: Research and development 45,797 29,121 16,676 57 % Selling, general and administrative 58,531 45,764 12,767 28 % Total operating expenses 104,328 74,885 29,443 39 % Loss from operations (97,235) (71,473) (25,762) 36 % Other income (expense): Interest income 4,602 326 4,276 1312 % Interest expense — (22) 22 (100) % Other expense (333) — (333) (100) % Total other income 4,269 304 3,965 1304 % Net loss $ (92,966) $ (71,169) $ (21,797) 31 % Revenue Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Revenue $ 15,493 $ 6,617 $ 8,876 134 % Revenue increased by $8.9 million, or 134%, from $6.6 million in 2021 to $15.5 million in 2022, due to sales of products related to the Proteograph Product Suite in the year ended December 31, 2022.
Biggest changeInterest Income Interest income consists of interest earned on cash, cash equivalents and investments. 92 Table of Contents Results of Operations Comparisons of the Years Ended December 31, 2023 and 2022 The following table summarizes our results of operations for the periods presented: Year ended December 31, Change 2023 2022 Amount % (dollars in thousands) Revenue: Product $ 8,506 $ 8,557 $ (51 ) (1 )% Service 2,016 913 1,103 121 % Related party 4,660 5,215 (555 ) (11 )% Grant and other 1,479 808 671 83 % Total revenue 16,661 15,493 1,168 8 % Cost of revenue: Product 5,398 5,459 (61 ) (1 )% Service 685 495 190 38 % Related party 1,430 1,989 (559 ) (28 )% Grant and other 642 457 185 40 % Total cost of revenue 8,155 8,400 (245 ) (3 )% Gross profit 8,506 7,093 1,413 20 % Operating expenses: Research and development 53,019 45,797 7,222 16 % Selling, general and administrative 58,950 58,531 419 1 % Total operating expenses 111,969 104,328 7,641 7 % Loss from operations (103,463 ) (97,235 ) (6,228 ) 6 % Other income (expense): Interest income 17,764 4,602 13,162 286 % Other expense (578 ) (333 ) (245 ) 74 % Total other income 17,186 4,269 12,917 303 % Net loss $ (86,277 ) $ (92,966 ) $ 6,689 (7 )% Revenue Year ended December 31, Change 2023 2022 Amount % (dollars in thousands) Revenue $ 16,661 $ 15,493 $ 1,168 8 % Revenue increased by $1.2 million, or 8%, from $15.5 million in 2022 to $16.7 million in 2023, primarily due to an increase in service revenue.
We expect our expenses to increase significantly in connection with our ongoing activities, as we: • broadly commercialize the Proteograph Product Suite; • attract, hire and retain qualified personnel; • continue to build our sales, marketing, service, support and distribution infrastructure as part of our commercialization efforts; • build-out and expand our in-house NP manufacturing capabilities; • continue to engage in research and development of other products and enhancements to the Proteograph Product Suite; • implement operational, financial and management information systems; • obtain, maintain, expand, and protect our intellectual property portfolio; and • build the infrastructure to operate and scale as a public company.
We expect our expenses to increase in connection with our ongoing activities, as we: • broadly commercialize the Proteograph Product Suite; • attract, hire and retain qualified personnel; • continue to build our sales, marketing, service, support and distribution infrastructure as part of our commercialization efforts; • build-out and expand our in-house NP manufacturing capabilities; • continue to engage in research and development of other products and enhancements to the Proteograph Product Suite; • implement operational, financial and management information systems; • obtain, maintain, expand, and protect our intellectual property portfolio; and • build the infrastructure to operate and scale as a public company.
Since we were incorporated in 2017, we have devoted substantially all of our resources to research and development activities, including with respect to the Proteograph Product Suite, building our commercial infrastructure including manufacturing, operations, sales and marketing and service and support functions, establishing and maintaining our intellectual property portfolio, hiring personnel, raising capital, becoming a publicly-traded company, and providing general and administrative support for these activities.
Since we were incorporated in 2017, we have devoted substantially all of our resources to research and development activities, including with respect to the Proteograph Product Suite, building our commercial infrastructure including manufacturing, operations, sales and marketing and service and support functions, establishing and maintaining our intellectual property portfolio, hiring personnel, raising capital, becoming and being a publicly-traded company, and providing general and administrative support for these activities.
While we currently perform some filling and packaging of the Proteograph assay and the related consumables, we may eventually have 77 our filling and packaging outsourced to a third party. We conduct vendor and component qualification for components provided by third-party suppliers and quality control tests on our NPs.
While we currently perform some filling and packaging of the Proteograph assay and the related consumables, we may eventually have our filling and packaging outsourced to a third party. We conduct vendor and component qualification for components provided by third-party suppliers and quality control tests on our NPs.
Our ability to generate product revenue sufficient to achieve profitability, if ever, will depend on the successful commercialization of the Proteograph Product Suite. We are commercializing the Proteograph Product Suite as an integrated solution comprised of consumables, our SP100 automation instrument and software.
Our ability to generate product and service revenue sufficient to achieve profitability, if ever, will depend on the successful commercialization of the Proteograph Product Suite. We are commercializing the Proteograph Product Suite as an integrated solution comprised of consumables, our SP100 automation instrument and software.
Factors that could cause or contribute to such differences include, but are not limited to, those identified below and those set forth under the section titled “Risk Factors.” Overview Our mission is to imagine and pioneer new ways to decode the secrets of the proteome to improve human health.
Factors that could cause or contribute to such differences include, but are not limited to, those identified below and those set forth under the section titled “Risk Factors.” Overview Our mission is to imagine and pioneer new ways to decode the biology of the proteome to improve human health.
Our first product, the Proteograph TM Product Suite (Proteograph), leverages our proprietary engineered nanoparticle (NP) technology to provide unbiased, deep, rapid and large-scale access to the proteome. The Proteograph Product Suite is an integrated solution that includes consumables, an automation instrument and software.
Our product, the Proteograph Product Suite (Proteograph), leverages our proprietary engineered nanoparticle (NP) technology to provide unbiased, deep, rapid and large-scale access to the proteome. The Proteograph Product Suite is an integrated solution that includes consumables, an automation instrument and software.
Recent Accounting Pronouncements See Note 2 to our consolidated financial statements included elsewhere in this Annual Report for more information about recent accounting pronouncements, the timing of their adoption, and our assessment, to the extent we have made one yet, of their potential impact on our financial condition of results of operations.
Recent Accounting Pronouncements See Note 2 to our consolidated financial statements included elsewhere in this Annual Report for more information about recent accounting pronouncements, the timing of their adoption, and our assessment, to the extent we have made one yet, of their potential impact on our financial condition of results of operations. 98 Table of Contents
Revenue is recorded net of discounts and sales taxes collected on behalf of governmental authorities. Customers are invoiced generally upon shipment, or upon order for services, and payment is typically due within 30 or 60 days. 84 Cash received from customers in advance of product shipment or providing services is recorded as a contract liability.
Revenue is recorded net of discounts and sales taxes collected on behalf of governmental authorities. Customers are invoiced generally upon shipment, or upon delivery of services, and payment is typically due within 30 or 60 days. Cash received from customers in advance of product shipment or providing services is recorded as a contract liability.
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations You should read the following discussion and analysis of our financial condition and results of operations together with our audited consolidated financial statements and related notes included elsewhere in this Annual Report.
Item 7. Mana gement’s Discussion and Analysis of Financial Condition and Results of Operations You should read the following discussion and analysis of our financial condition and results of operations together with our audited consolidated financial statements and related notes included elsewhere in this Annual Report.
We obtain some of the reagents and components used in the Proteograph workflow from third-party suppliers. While some of these reagents and components are currently sourced from a single supplier, these products are readily available from numerous suppliers.
We obtain some of the reagents and components used in the 90 Table of Contents Proteograph workflow from third-party suppliers. While some of these reagents and components are currently sourced from a single supplier, these products are readily available from numerous suppliers.
However, based on our cash on hand, we believe we will have adequate liquidity over the next twelve months following the date of this Annual Report to operate our business and to meet our cash requirements.
However, based on our cash, cash equivalents and investments, we believe we will have adequate liquidity over the next twelve months following the date of this Annual Report to operate our business and to meet our cash requirements.
Selling, General and Administrative Expenses Selling, general and administrative expenses consist primarily of employee compensation, including stock-based compensation, and related benefits for executive management, sales and marketing, service and support, finance, administration and human resources, legal, allocated overhead, professional service fees and other general overhead costs to support our operations.
Selling, General and Administrative Expenses Selling, general and administrative expenses consist primarily of employee compensation, including stock-based compensation, and benefits for executive management, sales and marketing, customer support, finance, administrative, human resources, legal functions, allocated costs, professional service fees and other general overhead costs to support our operations.
While our significant accounting policies are described in the notes to our consolidated financial statements, we believe that the following critical accounting policies are most important to understanding and evaluating our reported financial results. Revenue Recognition Our revenue is generated primarily from the sale of products and services.
While our significant accounting policies are described in the notes to our consolidated financial statements, we believe that the following critical accounting policies are most important to understanding and evaluating our reported financial results. 96 Table of Contents Revenue Recognition Our revenue is generated primarily from sales of products and services.
Non-cash charges primarily consisted of stock-based compensation of $33.7 million, $3.9 million of depreciation and amortization and $2.0 million of non-cash operating lease expense.
Non-cash charges primarily consisted of stock-based compensation of $33.7 million, $3.9 million of depreciation and amortization and $1.7 million of non-cash operating lease expense.
Product revenue consists of sales of an instrument with embedded software essential to the instrument’s functionality and consumables as well as platform evaluation agreements. Service revenue primarily consists of revenue received from the generation and analysis of proteomic data on behalf of our customers.
Product revenue consists of sales of an instrument with embedded software essential to the instrument’s functionality and consumables. Service revenue primarily consists of revenue received from the generation and analysis of proteomic data on behalf of our customers.
Investing Activities In 2022, cash used in investing activities was $122.7 million, which related to purchases of available-for-sale securities, net of proceeds from maturities, of $112.6 million, in addition to $10.3 million in payments primarily for laboratory equipment. 83 In 2021, cash used in investing activities was $170.9 million, which related to purchases of available-for-sale securities, net of proceeds from maturities, of $164.0 million, in addition to $6.9 million in payments primarily for laboratory equipment.
In 2022, cash used in investing activities was $122.7 million, which related to purchases of available-for-sale securities, net of proceeds from maturities, of $112.6 million, in addition to $10.3 million in payments primarily for laboratory equipment.
The increase was due to higher rates of interest earned on cash invested in money market funds, U.S. Treasury securities, commercial paper and corporate securities in 2022. 82 Liquidity and Capital Resources Since the date of our incorporation, we have not generated significant revenue from product sales and have incurred significant operating losses and negative cash flows from operations.
The increase was due to higher rates of interest earned on cash invested in money market funds, U.S. Treasury securities, commercial paper, corporate securities and government agency debt in 2023. Liquidity and Capital Resources Since the date of our incorporation, we have incurred significant operating losses and negative cash flows from operations.
Revenue recognized primarily consisted of sales of the Proteograph SP100 instrument, consumable kits and platform evaluations, of which $5.2 million was attributed to related parties.
Revenue recognized primarily consisted of sales of the Proteograph SP100 instrument, consumable kits, platform evaluations, instrument upgrades and service revenue, of which $4.7 million was attributed to related parties.
As of December 31, 2022, we had an accumulated deficit of $219.5 million and cash, cash equivalents, and investments of $426.4 million. We expect to continue to incur significant and increasing losses and do not expect positive cash flows from operations for the foreseeable future.
As of December 31, 2023, we had an accumulated deficit of $305.8 million and cash, cash equivalents, and investments of $373.1 million. We expect to continue to incur significant losses and do not expect positive cash flows from operations for the foreseeable future.
Financing Activities In 2022, cash provided by financing activities was $3.9 million. This was attributable to net proceeds from the exercise of stock options of $3.1 million and $0.8 million of proceeds from the issuance of common stock in connection with our employee stock purchase plan. In 2021, cash provided by financing activities was $116.6 million.
Financing Activities In 2023, cash provided by financing activities was $0.5 million, which was primarily attributable to proceeds of $0.4 million from the issuance of Class A common stock in connection with our employee stock purchase plan and net proceeds of $0.1 million from the exercise of stock options. In 2022, cash provided by financing activities was $3.9 million.
Cost of goods sold consists primarily of costs of the components of the Proteograph Product Suite, including the SP100 instrument with embedded software essential to the instrument’s functionality, and consumables, and distribution-related expenses such as logistics and shipping costs. In addition, cost of revenue includes stock-based compensation and related employee benefits, allocated overhead and write-downs or impairments of obsolete inventory.
Cost of revenue consists primarily of costs of the components of the Proteograph Product Suite, including the SP100 instrument and consumables and distribution-related expenses such as logistics and shipping costs. In addition, cost of revenue includes employee compensation, such as stock-based compensation and employee benefits, allocated overhead and charges related to inventory reserves.
Research and Development Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Research and development $ 45,797 $ 29,121 $ 16,676 57 % Research and development expenses increased by $16.7 million, or 57%, from $29.1 million in 2021 to $45.8 million in 2022.
Research and Development Year ended December 31, Change 2023 2022 Amount % (dollars in thousands) Research and development $ 53,019 $ 45,797 $ 7,222 16 % Research and development expenses increased by $7.2 million, or 16%, from $45.8 million in 2022 to $53.0 million in 2023.
Other increases include costs related to general business expenses of $1.0 million, which include IT support services and expensed software, a $0.7 million increase in laboratory expenses and a $0.8 million increase in depreciation of laboratory equipment.
Other increases include costs related to general business expenses of $0.6 million and a $1.3 million increase in depreciation of laboratory equipment.
Cash Flows The following table summarizes our cash flows for the periods indicated: Year ended December 31, 2022 2021 (in thousands) Net cash used in operating activities $ (60,780) $ (46,347) Net cash used in investing activities (122,718) (170,878) Net cash provided by financing activities 3,893 116,634 Net decrease in cash, cash equivalents and restricted cash $ (179,605) $ (100,591) Operating Activities In 2022, cash used in operating activities was $60.8 million, attributable to a net loss of $93.0 million, partially offset by a net change in our net operating assets and liabilities of $7.4 million and non-cash charges of $39.6 million.
Cash Flows The following table summarizes our cash flows for the periods indicated: Year ended December 31, 2023 2022 (in thousands) Net cash used in operating activities $ (59,065 ) $ (60,780 ) Net cash provided by (used in) investing activities 37,904 (122,718 ) Net cash provided by financing activities 452 3,893 Net decrease in cash, cash equivalents and restricted cash $ (20,709 ) $ (179,605 ) Operating Activities In 2023, cash used in operating activities was $59.1 million, attributable to a net loss of $86.3 million, partially offset by a net change in our net operating assets and liabilities of $2.7 million and non-cash charges of $29.9 million.
R&D expenses consist primarily of employee compensation, including stock-based compensation, and related employee benefits, laboratory supplies used for in-house research, consulting costs, costs related to clinical studies for the collection of biological samples for research use and allocated costs, rent, depreciation, information technology, and utilities.
Research and Development Expenses Research and development (R&D) expenses include costs associated with R&D of our technology and product candidates. R&D expenses consist primarily of employee compensation, including stock-based compensation and employee benefits, laboratory supplies used for in-house research, consulting costs, and allocated costs, including rent, depreciation, information technology and utilities.
Grant and other cost of revenue was attributed to the lease of the SP100 instruments. Cost of revenue related to the Proteograph Product Suite consists of costs of the SP100 instrument, consumable kits and other related costs, including labor and overhead.
Cost of revenue consists of costs of the SP100 instrument, consumable kits, cost of services, and other related costs, including labor and overhead.
Selling, General and Administrative Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Selling, general and administrative $ 58,531 $ 45,764 $ 12,767 28 % Selling, general and administrative expenses increased by $12.8 million, or 28%, from $45.8 million in 2021 to $58.5 million in 2022, primarily due to a $4.5 million increase in employee compensation and other related expenses, and a $3.8 million increase in stock-based compensation.
Selling, General and Administrative Year ended December 31, Change 2023 2022 Amount % (dollars in thousands) Selling, general and administrative $ 58,950 $ 58,531 $ 419 1 % Selling, general and administrative expenses increased by $0.4 million, or 1%, from $58.5 million in 2022 to $59.0 million in 2023, primarily due to a $3.3 million increase in employee compensation costs and a $0.1 million increase in travel expense.
We are broadly commercializing the Proteograph Product Suite through a direct sales channel in the United States, and through both direct and distributor sales channels in regions outside the United States. Since we are in the early stages of commercialization, we have built, and will continue to build our sales, marketing, support and product distribution capabilities.
Since we are in the early stages of commercialization, we have built, and will continue to build our sales, marketing, support and product distribution capabilities.
The increase was primarily due to an increase in product development efforts related to the Proteograph Product Suite including $5.6 million increase in employee compensation costs and other related expenses, and a $4.7 million increase in stock-based compensation, due to growth in research and development personnel, and a $4.0 million increase in allocated overhead related to the allocation of facility expense associated with the build-out of our expansion facilities to support our R&D efforts.
The increase was primarily due to an increase in product development efforts related to the Proteograph Product Suite, including $2.4 million increase in employee compensation costs, a $0.6 million increase in stock-based compensation, due to growth in research and development personnel and a $2.2 million increase in allocated costs.
Non-cash charges primarily consisted of $25.9 million in stock-based compensation, $2.6 million of depreciation and amortization, $1.2 million of net amortization of premiums on available-for-sales securities and $1.0 million of non-cash operating lease expense.
Non-cash charges primarily consisted of stock-based compensation of $34.4 million, $5.6 million of depreciation and amortization, $0.8 million of provision for inventory excess and obsolescence, $0.4 million of loss on disposal of property and equipment, and $0.2 million of non-cash operating lease expense, offset by $11.5 million of net accretion of premiums on available-for-sale securities.
Total Other Income Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Total other income $ 4,269 $ 304 $ 3,965 1304 % Total other income increased by $4.0 million, or 1304%, from $0.3 million in 2021 to $4.3 million in 2022.
The increase was offset by a $2.9 million decrease in professional services. Total Other Income Year ended December 31, Change 2023 2022 Amount % (dollars in thousands) Total other income $ 17,186 $ 4,269 $ 12,917 303 % Total other income increased by $12.9 million, or 303%, from $4.3 million in 2022 to $17.2 million in 2023.
Standalone lease arrangements are outside the scope of Accounting Standards Codification (ASC) 606, Revenue Contracts with Customer and are therefore accounted for in accordance with ASC 842, Leases . Each of these contracts is evaluated as a lease arrangement, either as an operating lease or a sales-type finance lease using the lease classification guidance.
Standalone lease arrangements are outside the scope of Accounting Standards Codification (ASC) 606, Revenue Contracts with Customer and are therefore accounted for in accordance with ASC 842, Leases . The total consideration in a lease arrangement is allocated between lease and non-lease components on their relative stand-alone selling prices.
The change in our net operating assets and liabilities was primarily due to an increase in inventory levels of $3.6 million, an increase in accounts receivable of $2.5 million and a decrease of $0.6 million in accrued research and development, which was partially offset by an increase in accounts payable of $1.6 million.
The change in our net operating assets and liabilities was primarily due to an increase in inventory levels of $1.9 million for anticipated revenue growth and a $1.3 million increase in prepaid expenses and other current assets, which was partially offset by a decrease in accounts receivable of $0.3 million. 95 Table of Contents In 2022, cash used in operating activities was $60.8 million, attributable to a net loss of $93.0 million, partially offset by a net change in our net operating assets and liabilities of $7.1 million and non-cash charges of $39.3 million.
This was attributable to net proceeds of $103.0 million from issuance of common stock upon initial public offering, net of issuance costs, $11.4 million in short-swing profits from a beneficial owner and $1.9 million from the exercise of stock options.
This was attributable to net proceeds from the exercise of stock options of $3.1 million and $0.8 million of proceeds from the issuance of Class A common stock in connection with our employee stock purchase plan.
We received net proceeds of $103.0 million after deducting offering costs, underwriting discounts and commissions. During the years ended December 31, 2022 and 2021, we incurred a net loss of $93.0 million and $71.2 million and used $60.8 million and $46.3 million of cash in operations, respectively.
Hamilton has represented to us that it maintains ISO 9001 and ISO 13485 certifications. During the years ended December 31, 2023 and 2022, we incurred a net loss of $86.3 million and $93.0 million and used $59.1 million and $60.8 million of cash in operations, respectively.
Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the options. • Expected dividend yield—We have never paid dividends on our common stock and have no plans to pay dividends on our common stock. Therefore, we used an expected dividend yield of zero.
The expected dividend yield is assumed to be zero as we have never paid dividends and have no current plans to pay dividends on our common stock.
The comparable companies were chosen based on their similar size, life cycle stage, or area of specialty. We will continue to apply this process until enough historical information regarding the volatility of our own stock price becomes available. • Risk-free interest rate—The risk-free interest rate is based on the U.S.
The comparable companies were chosen based on their similar size, life cycle stage, or area of specialty. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues in effect at the time of grant for periods corresponding with the expected term of the options.
The Black-Scholes model requires the input of subjective assumptions, including fair value of common stock, expected term, expected volatility, risk-free interest rate, and expected dividend yield, which are described in greater detail below.
The Black-Scholes option-pricing model considers several variables and assumptions in estimating the fair value of service-based stock options and stock purchase rights under our ESPP. These variables include the per share fair value of the underlying common stock, expected term, expected volatility, risk-free interest rate and expected dividend yield over the expected term.
Our grant-funded activities are expected to decrease as a percentage of total revenue as we decrease grant-funded activities and continue to ramp up commercialization of the Proteograph Product Suite. 79 Cost of Revenue We utilize third-party manufacturers for production of our SP100 instrument and we manufacture our NPs and assemble our assay kits internally.
We intend to focus our commercial efforts in the United States and expect to grow our international presence. 91 Table of Contents Cost of Revenue We utilize third-party manufacturers for production of our SP100 instrument and we manufacture our NPs and assemble our assay kits internally.
Revenue related to grant and other consisted of our grant-funded activities related to our Small Business Innovation Research (SBIR) grant from the National Institutes of Health Grant (NIH), which increased between the two periods by $45,000 and $0.5 million respectively, and lease arrangements where we are the lessor. 81 Cost of Revenue Year ended December 31, Change 2022 2021 Amount % (dollars in thousands) Cost of revenue $ 8,400 $ 3,205 $ 5,195 162 % Cost of revenue increased by $5.2 million, or 162%, from $3.2 million in 2021 to $8.4 million in 2022, primarily due to sales of the Proteograph Product Suite.
Revenue from our grant-funded activities related to our Small Business Innovation Research (SBIR) grant from the National Institutes of Health Grant (NIH) increased between the two periods by $0.9 million and was partially offset by a decrease of $0.4 million in lease revenue.
For additional details, see the section titled “Risk Factors.” Components of Results of Operations Revenue We generate revenue from product sales, including sales of the Proteograph Product Suite, which consists of an instrument with embedded software essential to the instrument’s functionality and associated consumables as well as our platform evaluation agreements.
Components of Results of Operations Revenue Our product revenue consists of an instrument with embedded software essential to the instrument’s functionality and consumables. Our service revenue primarily consists of revenue received from the generation and analysis of proteomic data on behalf of the customer. Our related party revenue consists primarily of product sales to related parties.
Stock-Based Compensation We account for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees and non-employees based on estimated grant-date fair values. We use the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period.
We estimate the fair value of stock options with service conditions and stock purchase rights under our ESPP on the grant date using the Black-Scholes option-pricing valuation model. We use the straight-line method to allocate compensation cost to reporting periods over the requisite service period in which the awards are expected to vest.
The expected term for options granted to non-employees is the contractual term. • Expected volatility—As we had no publicly available stock price information prior to our IPO and limited publicly available stock price information subsequent to our IPO, the expected volatility was estimated based on the historical average volatility for comparable publicly traded life sciences technology companies over a period equal to the expected term of the stock option grants.
For all service-based stock options granted, we calculate the expected term using the simplified method for “plain vanilla” stock option awards. For the expected volatility, we use a blended rate based on the historical volatility of the stock price of our Class A common stock and average volatility of our comparable publicly traded peer companies.