Form 4: Castle Biosciences Executive Sells Shares
Insider Transaction (Form 4)
Derek J Maetzold, Pres. & Chief Exec. Officer and a Director of Castle Biosciences Inc, sold 39,016 shares of common stock on August 4, 2026.
Summary
- Option exercise/conversion: acquired 20,356 Common Stock at $2.39 ($48,651) on August 4, 2026; holds 41,835 after (Direct).
- Open-market sale: disposed of 8,421 Common Stock at $30.79 ($259,266) on August 4, 2026; holds 33,414 after (Direct).
- Open-market sale: disposed of 3,374 Common Stock at $30.79 ($103,879) on August 4, 2026; holds 28,407 after (Indirect).
- Open-market sale: disposed of 2,866 Common Stock at $30.79 ($88,238) on August 4, 2026; holds 24,143 after (Indirect).
- Open-market sale: disposed of 11,935 Common Stock at $31.34 ($373,995) on August 4, 2026; holds 21,479 after (Direct).
- Open-market sale: disposed of 4,782 Common Stock at $31.34 ($149,849) on August 4, 2026; holds 23,625 after (Indirect).
- Open-market sale: disposed of 4,063 Common Stock at $31.34 ($127,318) on August 4, 2026; holds 20,080 after (Indirect).
- Option exercise/conversion: acquired 2,546 Common Stock at $2.39 ($6,085) on August 5, 2026; holds 24,025 after (Direct).
- Open-market sale: disposed of 2,546 Common Stock at $30.68 ($78,114) on August 5, 2026; holds 21,479 after (Direct).
- Open-market sale: disposed of 556 Common Stock at $30.68 ($17,059) on August 5, 2026; holds 23,069 after (Indirect).
- Open-market sale: disposed of 473 Common Stock at $30.68 ($14,512) on August 5, 2026; holds 19,607 after (Indirect).
- Option exercise/conversion: disposed of 20,356 Stock option (right to buy) on August 4, 2026; holds 41,403 after (Direct).
- Option exercise/conversion: disposed of 2,546 Stock option (right to buy) on August 5, 2026; holds 38,857 after (Direct).
Sentiment
Score: 4
Explanation: StockSavvy.ai views this as a mildly negative but low-conviction signal: an insider sold $1,212,230 of stock under a pre-arranged Rule 10b5-1 plan, which is typically routine.
Insider Transactions
Derek J Maetzold — Director, Officer (Pres. & Chief Exec. Officer)
Transaction made under a Rule 10b5-1 trading plan.
| Date | Transaction | Security | Shares | Price | Value | Held After |
|---|---|---|---|---|---|---|
| 2026-08-04 | Option exercise/conversion | Common Stock | 20,356 | $2 | $48.7K | 41,835 |
| 2026-08-04 | Open-market sale | Common Stock | 8,421 | $31 | $259.3K | 33,414 |
| 2026-08-04 | Open-market sale | Common Stock | 3,374 | $31 | $103.9K | 28,407 |
| 2026-08-04 | Open-market sale | Common Stock | 2,866 | $31 | $88.2K | 24,143 |
| 2026-08-04 | Open-market sale | Common Stock | 11,935 | $31 | $374.0K | 21,479 |
| 2026-08-04 | Open-market sale | Common Stock | 4,782 | $31 | $149.8K | 23,625 |
| 2026-08-04 | Open-market sale | Common Stock | 4,063 | $31 | $127.3K | 20,080 |
| 2026-08-05 | Option exercise/conversion | Common Stock | 2,546 | $2 | $6.1K | 24,025 |
| 2026-08-05 | Open-market sale | Common Stock | 2,546 | $31 | $78.1K | 21,479 |
| 2026-08-05 | Open-market sale | Common Stock | 556 | $31 | $17.1K | 23,069 |
| 2026-08-05 | Open-market sale | Common Stock | 473 | $31 | $14.5K | 19,607 |
| 2026-08-04 | Option exercise/conversion | Stock option (right to buy) | 20,356 | — | — | 41,403 |
| 2026-08-05 | Option exercise/conversion | Stock option (right to buy) | 2,546 | — | — | 38,857 |
Key Dates
| Date | Description |
|---|---|
| 2026-08-04 | Option exercise/conversion (20,356 shares) |
| 2026-08-04 | Open-market sale (8,421 shares) |
| 2026-08-04 | Open-market sale (3,374 shares) |
| 2026-08-04 | Open-market sale (2,866 shares) |
| 2026-08-04 | Open-market sale (11,935 shares) |
| 2026-08-04 | Open-market sale (4,782 shares) |
| 2026-08-04 | Open-market sale (4,063 shares) |
| 2026-08-05 | Option exercise/conversion (2,546 shares) |
| 2026-08-05 | Open-market sale (2,546 shares) |
| 2026-08-05 | Open-market sale (556 shares) |
| 2026-08-05 | Open-market sale (473 shares) |
| 2026-08-04 | Option exercise/conversion (20,356 shares) |
| 2026-08-05 | Option exercise/conversion (2,546 shares) |
Keywords
insider transaction, Form 4, CSTL, CASTLE BIOSCIENCES INC, bearish, Derek J Maetzold
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