Company profile
Castle Biosciences Inc Insider Trading
CSTLEvery SEC Form 4 insider trading filing for Castle Biosciences Inc (CSTL) since April 2023: open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC. Why 2023?
- Exchange
- Nasdaq
- Sector
- Services-Medical Laboratories
- CIK
- 0001447362
- Filings
- 253
- Insiders
- 12
- Last filing
- 2026-09-21
Activity summary
No discretionary insider buying or selling in the last 30 days. Of the 36 transactions filed, 28 were scheduled under a 10b5-1 plan and 8 were grants, option exercises or other non-open-market activity.
Three year balance
Buy and sell value by quarter, Q4 23 to Q3 26. Castle Biosciences Inc insiders were net sellers in every quarter shown.
Bars below the rule are sales, above are purchases. Largest quarter on the chart is $7.8M.
90 day insight
Over the last 90 days, Castle Biosciences Inc insiders sold $838K across 3 transactions with no open-market purchases.
- Most active insider: Derek J Maetzold with 38 transactions totaling $1.9M.
- Largest single sale: $412K by Kristen M Oelschlager on Aug 24, 2026.
- 93% of recent sales were pre-scheduled 10b5-1 trades, typically less informative than open-market activity.
Activity skews bearish: sales outpace buys.
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 21, 2026 | Derek J Maetzold | CSTL | Option Exercise10b5 | 8,580 | $2.39 | $21K |
| Sep 21, 2026 | Derek J Maetzold | CSTL | Sale10b5 | 8,580 | $35.33 | $303K |
| Sep 21, 2026 | Derek J Maetzold | CSTL | Sale10b5 | 3,198 | $35.33 | $113K |
| Sep 21, 2026 | Derek J Maetzold | CSTL | Sale10b5 | 2,718 | $35.33 | $96K |
| Sep 21, 2026 | Derek J Maetzold | CSTL | Option Exercise10b5 | 8,580 | — | — |
45 more transactions hidden
Free account · No credit card required
Building something? Get API access →
Query this yourself
The same rows, over the API.
curl "https://api.form4api.com/v1/transactions?ticker=CSTL" \
-H "X-Api-Key: $KEY"Top insiders
By open-market value traded.
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 →