// company-profile
Castle Biosciences Inc Insider Trading
CSTLEvery SEC Form 4 insider trading filing for Castle Biosciences Inc (CSTL) — open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC.
curl "https://api.form4api.com/v1/transactions?ticker=CSTL" -H "X-Api-Key: YOUR_API_KEY"// activity-summary
Mixed insider activity over the last 30 days: 0 purchases and 0 sales (0 transactions total).
// 90-day insight
Over the last 90 days, Castle Biosciences Inc insiders filed 50 Form 4 transactions, none of which were open-market purchases or sales.
- Most active insider: MAETZOLD DEREK J with 43 transactions totaling $2.4M.
- Largest single sale: $374K by MAETZOLD DEREK J on Aug 4, 2026.
- 100% of recent sales were pre-scheduled 10b5-1 trades — typically less informative than open-market activity.
Activity skews bullish — buys outpace sales.
Institutional Ownership
Top 13F-HR holders of Castle Biosciences Inc as of 2026-06-30
Data source: quarterly 13F-HR filings — institutional holders report positions within 45 days of quarter end. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 5, 2026 | MAETZOLD DEREK J | CSTL | Option Exercise10b5 | 2,546 | $0.00 | $0K |
| Aug 5, 2026 | MAETZOLD DEREK J | CSTL | Option Exercise10b5 | 2,546 | $2.39 | $6K |
| Aug 5, 2026 | MAETZOLD DEREK J | CSTL | Sale10b5 | 556 | $30.68 | $17K |
| Aug 5, 2026 | MAETZOLD DEREK J | CSTL | Sale10b5 | 473 | $30.68 | $15K |
| Aug 5, 2026 | MAETZOLD DEREK J | CSTL | Sale10b5 | 2,546 | $30.68 | $78K |
45 more transactions hidden
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