Stocks Health care CSTL
NASDAQ · Health careCastle Biosciences Inc (CSTL)
Castle Biosciences Inc brought in $357.3M of revenue over the twelve months to June 30, 2026, up 3.2% from a year earlier. It posted a net loss of $19.4M. Operating cash flow minus capital spending left $28.3M of free cash flow in fiscal 2025. At June 30, 2026 it held $62.1M in cash against $10.1M of debt. Its latest periodic report to the SEC is the quarterly report (10-Q) filed on July 30, 2026.
What Castle Biosciences Inc does
Castle Biosciences Inc is registered with the SEC under industry code SIC 8071 (Services-Medical Laboratories). Its shares trade on NASDAQ under the ticker CSTL.
Revenue and profit by year
Key figures
| Fiscal year | Revenue | Net income | Diluted EPS | Free cash flow |
|---|---|---|---|---|
| 2025 | $344.2M | -$24.2M | -$0.83 | $28.3M |
| 2024 | $332.1M | $18.2M | $0.62 | $36.5M |
| 2023 | $219.8M | -$57.5M | -$2.14 | -$19.2M |
| 2022 | $137M | -$67.1M | -$2.58 | -$47.3M |
| 2021 | $94.1M | -$31.3M | -$1.24 | -$22.5M |
| 2020 | $62.6M | -$10.3M | -$0.54 | $5.1M |
Where CSTL ranks in Health care
Latest SEC filings
What Castle Biosciences Inc has filed recently, newest first. Each links to the original document on SEC EDGAR.
- July 30, 2026Quarterly report 10-Q · period to June 30, 2026
- July 30, 2026
- May 29, 2026
- May 15, 2026Passive stake changed SCHEDULE 13G/A
- May 15, 2026Passive stake changed SCHEDULE 13G/A
- May 6, 2026Quarterly report 10-Q · period to March 31, 2026
- May 6, 2026
- April 8, 2026
- April 8, 2026Additional proxy material DEFA14A
- April 8, 2026Proxy statement DEF 14A
What is CSTL worth? A DCF from its reported cash flow
Insider trades
What the people running Castle Biosciences Inc did with its shares, from the Form 4 filings they must send the SEC within two business days.
Insiders sold $3.2M worth of shares in the last 90 days and bought none on the open market. Most of the selling (74%) was pre-planned under Rule 10b5-1 trading plans.
| Date | Insider | What | Shares | Value |
|---|---|---|---|---|
| September 21, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Exercised options | 8,580 | $20.5K |
| September 21, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1) | 8,580 | $303.2K |
| September 21, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 3,198 | $113K |
| September 21, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 2,718 | $96K |
| September 15, 2026 | Juvenal Tobin WChief Commercial Officer | Soldpre-planned (10b5-1) | 3,294 | $115.8K |
| September 14, 2026 | Juvenal Tobin WChief Commercial Officer | Soldpre-planned (10b5-1) | 3,306 | $106.9K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Exercised options | 8,584 | $20.5K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1) | 8,361 | $267.6K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 3,124 | $100K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 2,656 | $85K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1) | 223 | $7.3K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 83 | $2.7K |
| September 11, 2026 | Maetzold Derek JPres. & Chief Exec. Officer, Director | Soldpre-planned (10b5-1), indirect | 71 | $2.3K |
| September 1, 2026 | Oelschlager Kristen MChief Operating Officer | Exercised options | 4,152 | $14K |
| September 1, 2026 | Oelschlager Kristen MChief Operating Officer | Soldpre-planned (10b5-1) | 3,952 | $131.8K |
Questions about CSTL
What does Castle Biosciences Inc do?
Castle Biosciences Inc is registered with the SEC under industry code SIC 8071 (Services-Medical Laboratories). Its shares trade on NASDAQ under the ticker CSTL.
Is Castle Biosciences Inc profitable?
No. Over the twelve months to June 30, 2026 it reported a net loss of $19.4M on revenue of $357.3M.
How much revenue does Castle Biosciences Inc make?
Over the twelve months to June 30, 2026 Castle Biosciences Inc reported revenue of $357.3M. That is 3.2% more than a year earlier.
When did Castle Biosciences Inc last report?
Its most recent periodic report is the quarterly report (10-Q) filed on July 30, 2026. It covers the period to June 30, 2026. Its newest filing of any kind is the insider trade from September 23, 2026.
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Follow CSTL: get an email when it filesWhere the numbers come from
Financial figures are the values Castle Biosciences Inc tagged in its own SEC filings (XBRL), taken from the latest filing for each period, so restatements replace older figures. Revenue, profit and cash flow are for full fiscal years unless marked as the last twelve months, which is the sum of the four most recent quarters. Where a company reports only the full year, the fourth quarter is the year minus the first three.
Prices are delayed end-of-day market data in the listing currency, and market cap moves with the price. P/E is shown only when earnings per share are positive. Nothing here is investment advice.