📊 CSTL Key Takeaways
Investment Thesis
Castle Biosciences demonstrates strong revenue growth and excellent liquidity, but is severely unprofitable with negative operating and net margins that have dramatically deteriorated year-over-year. The company is burning through shareholder equity despite generating positive free cash flow, indicating unsustainable unit economics in its medical laboratory services business.
CSTL Strengths
- Strong liquidity position with 5.26x current ratio and $116.7M cash reserves
- Positive free cash flow of $28.3M provides runway despite losses
- Revenue growth of 3.7% YoY shows market demand for services
- Low leverage with debt/equity of 0.02x provides financial flexibility
CSTL Risks
- Gross margin of only 5.7% is critically low for a services business, indicating severe cost structure problems
- Net loss of $24.2M with deteriorating profitability (-232.4% YoY) shows worsening operational performance
- Operating margin of -12.4% with negative interest coverage (-2518.2x) indicates inability to cover fixed costs
- Unsustainable business model: positive FCF masks underlying operational losses that will deplete equity over time
Key Metrics to Watch
- Gross margin expansion - critical threshold is reaching 15%+ to support operations
- Path to operating profitability and timeline to positive EBITDA
- Operating expense reduction as percentage of revenue
- Cash burn rate and runway given current negative profitability trends
CSTL Financial Metrics
💡 AI Analyst Insight
Strong liquidity with a 5.26x current ratio provides a solid financial cushion.
CSTL Profitability Ratios
CSTL vs Healthcare Sector
How CASTLE BIOSCIENCES INC compares to Healthcare sector averages
Sector benchmarks are approximate industry averages. Actual sector performance may vary.
CSTL Balance Sheet & Liquidity
CSTL 5-Year Financial Trend
5-Year Trend Summary: CASTLE BIOSCIENCES INC's revenue has grown significantly by 266% over the 5-year period, indicating strong business expansion. The most recent EPS of $-2.14 indicates the company is currently unprofitable.
CSTL Growth Metrics (YoY)
CSTL Quarterly Performance
| Quarter | Revenue | Net Income | EPS |
|---|---|---|---|
| Q3 2025 | $83.0M | -$501.0K | $-0.02 |
| Q2 2025 | $86.2M | -$2.5M | $0.15 |
| Q1 2025 | $73.0M | -$2.5M | $-0.09 |
| Q3 2024 | $61.5M | $2.3M | $0.08 |
| Q2 2024 | $50.1M | -$2.5M | $0.22 |
| Q1 2024 | $42.0M | -$2.5M | $-0.09 |
| Q3 2023 | $37.0M | -$1.6M | $-0.26 |
| Q2 2023 | $34.8M | -$1.6M | $-0.06 |
Data sourced from SEC EDGAR 10-Q quarterly filings. Figures may represent quarterly or cumulative values.
CSTL Capital Allocation
CSTL SEC Filings
Access official SEC EDGAR filings for CASTLE BIOSCIENCES INC (CIK: 0001447362)
📋 Recent SEC Filings
| Date | Form | Document | Action |
|---|---|---|---|
| Mar 19, 2026 | 4 | xslF345X06/wk-form4_1773951683.xml | View → |
| Mar 17, 2026 | 4 | xslF345X05/wk-form4_1773779760.xml | View → |
| Mar 16, 2026 | 4 | xslF345X05/wk-form4_1773691674.xml | View → |
| Mar 13, 2026 | 4 | xslF345X05/wk-form4_1773432611.xml | View → |
| Mar 9, 2026 | 4 | xslF345X05/wk-form4_1773087231.xml | View → |
❓ Frequently Asked Questions about CSTL
What is the AI rating for CSTL?
CASTLE BIOSCIENCES INC (CSTL) has an AI rating of SELL with 78% confidence, based on fundamental analysis of SEC EDGAR filings.
What are CSTL's key strengths?
Strong liquidity position with 5.26x current ratio and $116.7M cash reserves. Positive free cash flow of $28.3M provides runway despite losses.
What are the risks of investing in CSTL?
Gross margin of only 5.7% is critically low for a services business, indicating severe cost structure problems. Net loss of $24.2M with deteriorating profitability (-232.4% YoY) shows worsening operational performance.
What is CSTL's revenue and growth?
CASTLE BIOSCIENCES INC reported revenue of $344.2M.
Does CSTL pay dividends?
CASTLE BIOSCIENCES INC does not currently pay dividends.
Where can I find CSTL SEC filings?
Official SEC filings for CASTLE BIOSCIENCES INC (CIK: 0001447362) including 10-K, 10-Q, and 8-K reports are available on SEC EDGAR.
What is CSTL's EPS?
CASTLE BIOSCIENCES INC has a diluted EPS of $-0.83.
How is the AI analysis conducted?
Our AI (Claude) analyzes publicly available SEC EDGAR filings including 10-K annual reports and 10-Q quarterly reports to evaluate financial health, profitability ratios, balance sheet strength, and growth metrics.