Castle Biosciences Inc
NASDAQ: CSTL · HEALTHCARE · DIAGNOSTICS & RESEARCH
Updated 2026-06-05
Castle Biosciences Inc (CSTL) Financial statements
SEC filings — annual and quarterly data.
Income statement — annual
| Item | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|---|---|---|
| Revenue | $13.75M | $22.79M | $51.87M | $62.65M | $94.08M | $137.04M | $219.79M | $332.07M | $344.23M |
| Revenue growth (YoY) | — | +65.7% | +127.6% | +20.8% | +50.2% | +45.7% | +60.4% | +51.1% | +3.7% |
| Cost of revenue | $4.92M | $5.30M | $7.31M | $9.69M | $15.82M | $32.01M | $44.98M | $60.20M | $71.03M |
| Gross profit | $8.83M | $17.49M | $44.55M | $52.96M | $78.26M | $105.03M | $174.81M | $271.86M | $273.20M |
| Gross margin | 64.2% | 76.8% | 85.9% | 84.5% | 83.2% | 76.6% | 79.5% | 81.9% | 79.4% |
| R&D | $4.47M | $4.85M | $7.38M | $13.26M | $29.65M | $44.90M | $53.62M | $52.04M | $51.85M |
| SG&A | $15.26M | $16.47M | $29.84M | $48.13M | $86.74M | $56.40M | $66.50M | $76.58M | $91.21M |
| Operating income | $-10.90M | $-3.84M | $7.33M | $-6.54M | $-40.08M | $-72.86M | $-67.98M | $8.67M | $-42.81M |
| Operating margin | -79.2% | -16.8% | 14.1% | -10.4% | -42.6% | -53.2% | -30.9% | 2.6% | -12.4% |
| EBITDA | $-10.40M | $-3.76M | $10.28M | $-7.09M | $-36.60M | $-58.34M | $-45.02M | $38.14M | $11.34M |
| EBITDA margin | -75.6% | -16.5% | 19.8% | -11.3% | -38.9% | -42.6% | -20.5% | 11.5% | 3.3% |
| EBIT | $-10.71M | $-4.08M | $9.92M | $-7.57M | $-40.01M | $-68.89M | $-57.35M | $22.14M | $-29.43M |
| Interest expense | $1.65M | $2.27M | $4.57M | $2.63M | $1000.00 | $17000.00 | $11000.00 | $577000.00 | $86000.00 |
| Income tax | — | — | — | — | — | — | — | — | — |
| Effective tax rate | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% |
| Net income | $-12.37M | $-6.37M | $5.28M | $-10.28M | $-31.29M | $-67.14M | $-57.47M | $18.25M | $-24.16M |
| Net income growth (YoY) | — | +48.5% | +182.9% | -294.9% | -204.3% | -114.6% | +14.4% | +131.7% | -232.4% |
| Profit margin | -89.9% | -27.9% | 10.2% | -16.4% | -33.3% | -49.0% | -26.1% | 5.5% | -7.0% |
Frequently asked questions
What is Castle Biosciences Inc's revenue?
Castle Biosciences Inc's trailing twelve-month revenue is $339.92M. Revenue is the top line the whole model builds on, and at this scale the question shifts from how fast it grows to whether margins hold as it compounds.
How profitable is CSTL?
In its most recent fiscal year, CSTL ran a gross margin of 79.37%, an operating margin of -12.44%, and a net margin of -7.02%. Margins this high mean most of each extra dollar of revenue drops through to profit, which is the signature of real pricing power.
How much free cash flow does CSTL generate?
CSTL produced $28.33M in free cash flow in its most recent fiscal year. Free cash flow is what is left after running and reinvesting in the business, and it is the cash that actually funds buybacks, dividends, and a stronger balance sheet.
Is CSTL's balance sheet healthy?
CSTL holds $116.73M in cash and equivalents against $9.64M in long-term debt, on $470.87M of shareholder equity. Cash on hand exceeds long-term debt, so the balance sheet adds little financial risk to the thesis.