Castle Biosciences Inc
CSTL- Exchange
- Nasdaq
- Industry
- Services-Medical Laboratories
- SEC CIK
- 0001447362
In the last 90 days, Castle Biosciences Inc insiders filed 0 open-market purchases and 20 sales; 176 institutions reported holding it in 13F filings for Q2 2026, worth $653.8M in total; no superinvestor holds it.
Key figures
- Insider buysOpen market, last 90 days
- 0
- Insider sellsLast 90 days, $7.90M in total
- 20
- 13F holdersQ2 2026, −7 vs. previous quarter
- 176
- 13F valueReported value at the end of Q2 2026
- $653.8M
- Superinvestors holdingAt the end of Q2 2026
- 0
Price chart
Superinvestors holding CSTL, Q2 2026
No superinvestor reported holding CSTL at the end of Q2 2026.
Latest insider trades
Open-market purchases and sales by Castle Biosciences Inc insiders from Form 4, newest first.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Sep 23, 2026 (view filing)4:27 PM ET | Sep 21 | 2 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −8.58K | $35.33 | −$303.2K | −28.5%21.5K after | 10b5-1 |
| Sep 23, 2026 (view filing)4:27 PM ET | Sep 21 | 2 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −5.92K | $35.33 | −$209.0K | −38.3%9.55K after | 2 lots10b5-1 |
| Sep 16, 2026 (view filing)4:20 PM ET | Sep 14-15 | 2 days | Juvenal Tobin WChief Commercial Officer | SSale | −6.60K | $33.73 | −$222.6K | −10.1%58.6K after | 2 lots10b5-1 |
| Sep 15, 2026 (view filing)4:08 PM ET | Sep 11 | 4 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −8.58K | $32.02 | −$274.9K | −28.6%21.5K after | 2 lots10b5-1 |
| Sep 15, 2026 (view filing)4:08 PM ET | Sep 11 | 4 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −5.93K | $32.02 | −$190.0K | −32.6%12.3K after | 4 lots10b5-1 |
| Sep 3, 2026 (view filing)4:07 PM ET | Sep 1 | 2 days | Oelschlager Kristen MChief Operating Officer | SSale | −4.15K | $33.39 | −$138.6K | −23.7%13.4K after | 2 lots10b5-1 |
| Sep 2, 2026 (view filing)4:07 PM ET | Aug 31 | 2 days | Juvenal Tobin WChief Commercial Officer | SSale | −1.73K | $32.81 | −$56.8K | −2.6%65.2K after | 10b5-1 |
| Sep 1, 2026 (view filing)4:12 PM ET | Aug 28 | 4 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −12.4K | $33.20 | −$412.6K | −36.7%21.5K after | 2 lots10b5-1 |
| Sep 1, 2026 (view filing)4:12 PM ET | Aug 28 | 4 days | Maetzold Derek JPres. & Chief Exec. Officer | SSale | −6.13K | $33.20 | −$203.6K | −35.3%11.3K after | 12 lots10b5-1 |
| Aug 27, 2026 (view filing)4:38 PM ET | Aug 25 | 2 days | Juvenal Tobin WChief Commercial Officer | SSale | −9.05K | $35.04 | −$317.1K | −11.9%66.9K after | 10b5-1 |
Top 10 13F holders, Q2 2026
The largest institutional positions in Castle Biosciences Inc at the end of Q2 2026; share changes are against Q1 2026.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| BlackRock, Inc. | 3,291,963 | $78.5M | 0.00% | +309,017+10.4% | Added |
| RTW Investments, LP | 2,778,335 | $66.3M | 0.57% | +20,000+0.7% | Added |
| Principal Financial Group Inc | 1,726,648 | $41.2M | 0.02% | −43,229−2.4% | Reduced |
| Vanguard Capital Management LLC | 1,226,497 | $29.3M | 0.00% | +48,975+4.2% | Added |
| Acadian Asset Management LLC | 918,668 | $21.9M | 0.03% | +434,227+89.6% | Added |
| Allianz Asset Management GmbH | 879,258 | $21.0M | 0.02% | +67,934+8.4% | Added |
| Vanguard Portfolio Management LLC | 840,785 | $20.1M | 0.00% | −20,986−2.4% | Reduced |
| Summit Partners Public Asset Management, LLC | 824,872 | $19.7M | 0.51% | −115,813−12.3% | Reduced |
| State Street Corp | 822,079 | $19.6M | 0.00% | +53,000+6.9% | Added |
| Geode Capital Management, LLC | 795,912 | $19.0M | 0.00% | +67,812+9.3% | Added |