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Side-by-side financial comparison of CASTLE BIOSCIENCES INC (CSTL) and InterDigital, Inc. (IDCC). Click either name above to swap in a different company.

InterDigital, Inc. is the larger business by last-quarter revenue ($158.2M vs $87.0M, roughly 1.8× CASTLE BIOSCIENCES INC). On growth, CASTLE BIOSCIENCES INC posted the faster year-over-year revenue change (0.8% vs -37.4%). InterDigital, Inc. produced more free cash flow last quarter ($528.6M vs $19.7M). Over the past eight quarters, CASTLE BIOSCIENCES INC's revenue compounded faster (9.2% CAGR vs -22.5%).

Castle Biosciences Inc. is a commercial-stage diagnostic firm that develops and markets proprietary, clinically actionable tests for dermatological conditions such as melanoma and other skin cancers, plus rare diseases. It operates mainly in the U.S. healthcare market, focusing on segments with high unmet need for more accurate diagnostics to guide treatment choices.

InterDigital, Inc. is an American technology research and development company that provides wireless and video technologies for mobile devices, networks, and services worldwide. Founded in 1972, InterDigital is listed on the Nasdaq and is included in the S&P 600 index.

CSTL vs IDCC — Head-to-Head

Bigger by revenue
IDCC
IDCC
1.8× larger
IDCC
$158.2M
$87.0M
CSTL
Growing faster (revenue YoY)
CSTL
CSTL
+38.2% gap
CSTL
0.8%
-37.4%
IDCC
More free cash flow
IDCC
IDCC
$508.8M more FCF
IDCC
$528.6M
$19.7M
CSTL
Faster 2-yr revenue CAGR
CSTL
CSTL
Annualised
CSTL
9.2%
-22.5%
IDCC

Income Statement — Q4 FY2025 vs Q4 FY2025

Metric
CSTL
CSTL
IDCC
IDCC
Revenue
$87.0M
$158.2M
Net Profit
$43.0M
Gross Margin
79.0%
Operating Margin
-4.4%
30.2%
Net Margin
27.2%
Revenue YoY
0.8%
-37.4%
Net Profit YoY
-67.7%
EPS (diluted)
$-0.06
$1.07

Green = leading value per metric. Periods may differ when fiscal calendars don't align.

8-Quarter Revenue & Profit Trend

Side-by-side quarterly history. Quarters aligned by calendar period so offset fiscal years line up.

Revenue
CSTL
CSTL
IDCC
IDCC
Q4 25
$87.0M
$158.2M
Q3 25
$83.0M
$164.7M
Q2 25
$86.2M
$300.6M
Q1 25
$88.0M
$210.5M
Q4 24
$86.3M
$252.8M
Q3 24
$85.8M
$128.7M
Q2 24
$87.0M
$223.5M
Q1 24
$73.0M
$263.5M
Net Profit
CSTL
CSTL
IDCC
IDCC
Q4 25
$43.0M
Q3 25
$-501.0K
$67.5M
Q2 25
$4.5M
$180.6M
Q1 25
$-25.8M
$115.6M
Q4 24
$133.1M
Q3 24
$2.3M
$34.2M
Q2 24
$8.9M
$109.7M
Q1 24
$-2.5M
$81.7M
Gross Margin
CSTL
CSTL
IDCC
IDCC
Q4 25
79.0%
Q3 25
77.5%
Q2 25
79.5%
Q1 25
81.4%
Q4 24
81.3%
Q3 24
81.8%
Q2 24
83.3%
Q1 24
81.0%
Operating Margin
CSTL
CSTL
IDCC
IDCC
Q4 25
-4.4%
30.2%
Q3 25
-8.2%
46.0%
Q2 25
-4.9%
68.3%
Q1 25
-31.7%
62.6%
Q4 24
4.7%
64.3%
Q3 24
5.9%
30.6%
Q2 24
5.8%
59.9%
Q1 24
-7.5%
39.4%
Net Margin
CSTL
CSTL
IDCC
IDCC
Q4 25
27.2%
Q3 25
-0.6%
41.0%
Q2 25
5.2%
60.1%
Q1 25
-29.4%
54.9%
Q4 24
52.7%
Q3 24
2.6%
26.6%
Q2 24
10.3%
49.1%
Q1 24
-3.5%
31.0%
EPS (diluted)
CSTL
CSTL
IDCC
IDCC
Q4 25
$-0.06
$1.07
Q3 25
$-0.02
$1.93
Q2 25
$0.15
$5.35
Q1 25
$-0.90
$3.45
Q4 24
$0.32
$4.12
Q3 24
$0.08
$1.14
Q2 24
$0.31
$3.93
Q1 24
$-0.09
$2.88

Balance Sheet & Financial Strength

Snapshot of each company's liquidity, leverage and book value from the latest quarter.

Metric
CSTL
CSTL
IDCC
IDCC
Cash + ST InvestmentsLiquidity on hand
$299.5M
$1.2B
Total DebtLower is stronger
$10.1M
$16.3M
Stockholders' EquityBook value
$470.9M
$1.1B
Total Assets
$578.6M
$2.1B
Debt / EquityLower = less leverage
0.02×
0.01×

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
CSTL
CSTL
IDCC
IDCC
Q4 25
$299.5M
$1.2B
Q3 25
$287.5M
$1.3B
Q2 25
$275.9M
$937.0M
Q1 25
$275.2M
$883.3M
Q4 24
$293.1M
$958.2M
Q3 24
$95.0M
$813.2M
Q2 24
$85.6M
$760.3M
Q1 24
$82.9M
$984.6M
Total Debt
CSTL
CSTL
IDCC
IDCC
Q4 25
$10.1M
$16.3M
Q3 25
$10.0M
$17.1M
Q2 25
$10.0M
$16.6M
Q1 25
$10.0M
$16.0M
Q4 24
$10.0M
$15.4M
Q3 24
$10.0M
$18.3M
Q2 24
$10.0M
$17.7M
Q1 24
$10.0M
$28.0M
Stockholders' Equity
CSTL
CSTL
IDCC
IDCC
Q4 25
$470.9M
$1.1B
Q3 25
$467.0M
$1.1B
Q2 25
$455.4M
$1.1B
Q1 25
$440.3M
$936.9M
Q4 24
$455.8M
$857.2M
Q3 24
$441.1M
$722.5M
Q2 24
$423.9M
$696.8M
Q1 24
$402.5M
$624.3M
Total Assets
CSTL
CSTL
IDCC
IDCC
Q4 25
$578.6M
$2.1B
Q3 25
$562.8M
$2.1B
Q2 25
$544.7M
$2.0B
Q1 25
$501.7M
$1.9B
Q4 24
$531.2M
$1.8B
Q3 24
$514.6M
$1.7B
Q2 24
$487.3M
$1.6B
Q1 24
$458.5M
$1.8B
Debt / Equity
CSTL
CSTL
IDCC
IDCC
Q4 25
0.02×
0.01×
Q3 25
0.02×
0.02×
Q2 25
0.02×
0.02×
Q1 25
0.02×
0.02×
Q4 24
0.02×
0.02×
Q3 24
0.02×
0.03×
Q2 24
0.02×
0.03×
Q1 24
0.02×
0.04×

Cash Flow & Capital Efficiency

How much cash each business actually produces after reinvestment. Cash flow is harder to manipulate than net income.

Metric
CSTL
CSTL
IDCC
IDCC
Operating Cash FlowLast quarter
$26.9M
$544.5M
Free Cash FlowOCF − Capex
$19.7M
$528.6M
FCF MarginFCF / Revenue
22.7%
334.0%
Capex IntensityCapex / Revenue
8.3%
10.0%
Cash ConversionOCF / Net Profit
12.67×
TTM Free Cash FlowTrailing 4 quarters
$28.3M
$994.0M

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
CSTL
CSTL
IDCC
IDCC
Q4 25
$26.9M
$544.5M
Q3 25
$22.6M
$395.9M
Q2 25
$20.8M
$105.1M
Q1 25
$-6.0M
$-20.0M
Q4 24
$24.4M
$271.5M
Q3 24
$23.3M
$77.6M
Q2 24
$24.0M
$-48.9M
Q1 24
$-6.8M
$50.8M
Free Cash Flow
CSTL
CSTL
IDCC
IDCC
Q4 25
$19.7M
$528.6M
Q3 25
$7.8M
$395.3M
Q2 25
$11.6M
$104.5M
Q1 25
$-10.8M
$-34.5M
Q4 24
$16.8M
$265.7M
Q3 24
$17.0M
$76.7M
Q2 24
$18.8M
$-49.5M
Q1 24
$-16.0M
$50.3M
FCF Margin
CSTL
CSTL
IDCC
IDCC
Q4 25
22.7%
334.0%
Q3 25
9.4%
240.1%
Q2 25
13.4%
34.8%
Q1 25
-12.2%
-16.4%
Q4 24
19.5%
105.1%
Q3 24
19.8%
59.6%
Q2 24
21.6%
-22.1%
Q1 24
-21.9%
19.1%
Capex Intensity
CSTL
CSTL
IDCC
IDCC
Q4 25
8.3%
10.0%
Q3 25
17.9%
0.4%
Q2 25
10.7%
0.2%
Q1 25
5.4%
6.9%
Q4 24
8.8%
2.3%
Q3 24
7.4%
0.7%
Q2 24
6.0%
0.3%
Q1 24
12.5%
0.2%
Cash Conversion
CSTL
CSTL
IDCC
IDCC
Q4 25
12.67×
Q3 25
5.87×
Q2 25
4.60×
0.58×
Q1 25
-0.17×
Q4 24
2.04×
Q3 24
10.29×
2.27×
Q2 24
2.69×
-0.45×
Q1 24
0.62×

Financial Flow Comparison

Revenue → gross profit → operating profit → net profit for each company.

Revenue Breakdown by Segment

CSTL
CSTL

Dermatologic$48.6M56%
Non Dermatologic$38.4M44%

IDCC
IDCC

Segment breakdown not available.

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