Revenue growth has decelerated significantly, culminating in a 4.9% contraction in 2026Q1 alongside negative operating margins of -17.2%.
| Sales/Revenue | 339.92M | 344.23M | 332.07M | 219.79M | 137.04M | 94.08M | 62.65M | 51.87M | 22.79M | 13.75M |
| Revenue Growth % | -2.06% | 3.66% | 51.09% | 60.38% | 45.65% | 50.18% | 20.79% | 127.62% | 65.67% | - |
| Cost of Goods Sold | 54.65M | 71.03M | 60.2M | 44.98M | 32.01M | 15.82M | 9.69M | 7.31M | 5.3M | 4.92M |
| COGS % of Revenue | - | 20.63% | 18.13% | 20.47% | 23.36% | 16.82% | 15.46% | 14.09% | 23.25% | 35.79% |
| Gross Profit | 201.6M | 273.2M | 271.86M | 174.81M | 105.03M | 78.26M | 52.96M | 44.55M | 17.49M | 8.83M |
| Gross Margin % | 59.31% | 79.37% | 81.87% | 79.53% | 76.64% | 83.18% | 84.54% | 85.91% | 76.75% | 64.21% |
| Gross Profit Growth % | - | 0.49% | 55.52% | 66.43% | 34.2% | 47.77% | 18.87% | 154.76% | 98.02% | - |
| Operating Expenses | 318.56M | 316.01M | 263.19M | 242.78M | 177.88M | 118.34M | 59.51M | 37.23M | 21.32M | 19.73M |
| OpEx % of Revenue | - | 91.8% | 79.26% | 110.46% | 129.81% | 125.78% | 94.98% | 71.78% | 93.59% | 143.46% |
| Selling, General & Admin | 235.6M | 229.32M | 200.05M | 180.15M | 143M | 86.74M | 48.13M | 29.84M | 16.47M | 15.26M |
| SG&A % of Revenue | - | 66.62% | 60.24% | 81.97% | 104.35% | 92.19% | 76.83% | 57.54% | 72.28% | 110.94% |
| Research & Development | 53.69M | 51.85M | 52.04M | 53.62M | 44.9M | 29.65M | 13.26M | 7.38M | 4.85M | 4.47M |
| R&D % of Revenue | - | 15.06% | 15.67% | 24.4% | 32.77% | 31.51% | 21.16% | 14.24% | 21.3% | 32.52% |
| Other Operating Expenses | 4M | 34.84M | 11.11M | 9.01M | -10.02M | 1.96M | -1.88M | 0 | 0 | 163.29K |
| Operating Income | -29.3M | -42.81M | 8.67M | -67.98M | -72.86M | -40.08M | -6.54M | 7.33M | -3.84M | -10.9M |
| Operating Margin % | -8.62% | -12.44% | 2.61% | -30.93% | -53.16% | -42.6% | -10.44% | 14.13% | -16.83% | -79.25% |
| Operating Income Growth % | - | -593.77% | 112.75% | 6.7% | -81.78% | -512.64% | -189.27% | 291.05% | 64.81% | - |
| EBITDA | -16.47M | -2.04M | 24.67M | -55.65M | -62.31M | -36.67M | -6.07M | 7.69M | -3.51M | -10.59M |
| EBITDA Margin % | -4.85% | -0.59% | 7.43% | -25.32% | -45.47% | -38.98% | -9.69% | 14.82% | -15.42% | -76.99% |
| EBITDA Growth % | -157.53% | -108.27% | 144.33% | 10.7% | -69.92% | -504.15% | -178.97% | 318.81% | 66.83% | - |
| D&A (Non-Cash Add-back) | 12.82M | 40.77M | 16M | 12.33M | 10.54M | 3.41M | 472K | 358K | 323.02K | 310.82K |
| EBIT | -17.61M | -29.43M | 22.14M | -57.35M | -68.89M | -40.01M | -7.57M | 9.92M | -4.08M | -10.71M |
| Net Interest Income | 8.6M | 11.69M | 12.34M | 10.61M | 3.95M | 67K | -2.26M | -4.26M | -2.25M | -1.62M |
| Interest Income | 11.22M | 11.77M | 12.92M | 10.62M | 3.97M | 68K | 373K | 312K | 23.51K | 26.18K |
| Interest Expense | -65K | 86K | 577K | 11K | 17K | 1K | 2.63M | 4.57M | 2.27M | 1.65M |
| Other Income/Expense | 11.64M | 13.3M | 12.89M | 10.61M | 3.95M | 67K | -3.66M | -1.98M | -2.52M | -1.46M |
| Pretax Income | -17.66M | -29.51M | 21.56M | -57.37M | -68.9M | -40.01M | -10.2M | 5.35M | -6.36M | -12.36M |
| Pretax Margin % | -5.19% | -8.57% | 6.49% | -26.1% | -50.28% | -42.53% | -16.28% | 10.31% | -27.91% | -89.86% |
| Income Tax | -4.82M | -5.36M | 3.32M | 101K | -1.77M | -8.72M | 84K | 72K | 8.61K | 9.73K |
| Effective Tax Rate % | 27.32% | 18.15% | 15.39% | -0.18% | 2.56% | 21.79% | -0.82% | 1.35% | -0.14% | -0.08% |
| Net Income | -12.83M | -24.16M | 18.25M | -57.47M | -67.14M | -31.29M | -10.28M | 5.28M | -6.37M | -12.37M |
| Net Margin % | -3.77% | -7.02% | 5.49% | -26.15% | -48.99% | -33.26% | -16.42% | 10.17% | -27.94% | -89.93% |
| Net Income Growth % | -153.15% | -232.41% | 131.75% | 14.41% | -114.55% | -204.28% | -294.88% | 182.88% | 48.53% | - |
| Net Income (Continuing) | -12.83M | -24.16M | 18.25M | -57.47M | -67.14M | -31.29M | -10.28M | 5.28M | -6.37M | -12.37M |
| Discontinued Operations | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Minority Interest | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| EPS (Diluted) | -0.43 | -0.83 | 0.62 | -2.14 | -2.58 | -1.24 | -0.54 | -0.21 | -0.60 | -1.26 |
| EPS Growth % | -126.5% | -233.87% | 128.97% | 17.05% | -108.06% | -129.63% | -157.14% | 65% | 52.38% | - |
| EPS (Basic) | - | -0.83 | 0.66 | -2.14 | -2.58 | -1.24 | -0.54 | 0.35 | -0.60 | -1.26 |
| Diluted Shares Outstanding | 29.89M | 28.99M | 29.25M | 26.8M | 26.05M | 25.14M | 18.93M | 8.66M | 10.65M | 9.78M |
| Basic Shares Outstanding | 29.89M | 28.99M | 27.78M | 26.8M | 26.05M | 25.14M | 18.93M | 8.58M | 10.65M | 9.78M |
| Dividend Payout Ratio | - | - | - | - | - | - | - | - | - | - |
Medicare reimbursement policy volatility
According to recent financial filings, Castle Biosciences has experienced a notable deceleration in top-line expansion, with revenue growth shifting from high double-digit percentages in early 2024 to a contraction of 4.9% in 2026Q1, suggesting that market penetration for core diagnostic tests may be reaching saturation.
The transition from rapid growth to recent revenue contraction indicates that the company's reliance on its core dermatologic portfolio may be hitting a ceiling. Investors should monitor whether the newer gastroenterology and mental health segments can achieve sufficient scale to offset the slowing momentum in the established melanoma business.
As reported in financial statements, the company has historically maintained robust gross margins near 79%, reflecting the high value of its proprietary diagnostic reports, though the lack of reported COGS in 2026Q1 warrants further investigation into potential shifts in accounting or operational cost recognition.
The consistent gross margin profile suggests strong pricing power and a favorable cost-to-value ratio for its diagnostic tests. However, the sustainability of these margins appears contingent on maintaining high reimbursement rates, as any downward pressure from Medicare or private payers could rapidly erode this core profitability metric.
Based on the company's reported figures, operating expenses, particularly SG&A, have consistently outpaced gross profit growth, resulting in negative operating margins that reached -17.2% in 2026Q1, indicating that the firm has yet to achieve the necessary scale to leverage its significant commercial infrastructure investments.
The persistent gap between gross profit and operating income suggests that the company is prioritizing aggressive market expansion and clinician education over immediate profitability. This strategy appears to be a double-edged sword, as it builds long-term clinical utility but keeps the firm in a high-burn state that requires constant capital discipline.
Analysis of the income statement reveals that stock-based compensation remains a significant recurring expense, often exceeding $11 million per quarter, which complicates the assessment of true operational profitability and suggests that reported net income figures may not fully reflect the underlying cash-generating capacity of the business.
The reliance on equity-based incentives appears to be a structural component of the company's compensation model, which may mask the true cost of talent acquisition and retention. Investors should carefully adjust for these non-cash charges when evaluating the company's progress toward a sustainable, cash-flow-positive operating model.
Quick answers to the most common questions about buying CSTL stock.
For fiscal year 2025, Castle Biosciences, Inc. (CSTL) reported total revenue of $344.2M. This represents a 2402.8% increase compared to $13.8M in 2017.
Castle Biosciences, Inc. (CSTL) reported a net loss of $24.2M for the fiscal year ending 2025.
Castle Biosciences, Inc. (CSTL) reported an operating income of $-42.8M, resulting in an operating profit margin of -12.4%. This margin reflects the operational efficiency of the business before interest and taxes.
Castle Biosciences, Inc. (CSTL) generated $273.2M in gross profit for the year, representing a gross profit margin of 79.4%. This demonstrates the company's core pricing power and production efficiency.