MAETZOLD DEREK J 4
4 · CASTLE BIOSCIENCES INC · Filed Feb 5, 2026
Research Summary
AI-generated summary of this filing
Castle Biosciences (CSTL) CEO Derek Maetzold Sells Shares
What Happened
Derek J. Maetzold, President, CEO and Director of Castle Biosciences (CSTL), sold a total of 4,017 shares in open-market transactions on February 3–4, 2026, generating about $158,757. The filings report three disposals: 3,200 shares at a weighted-average $39.91 ($127,722), 646 shares at $37.82 ($24,433), and 171 shares at $38.61 (~$6,602). These were sales (S), not purchases.
Key Details
- Transaction dates: Feb 3, 2026 (3,200 shares) and Feb 4, 2026 (646 shares and 171 shares).
- Reported prices and ranges:
- 3,200 shares — weighted avg $39.91; executed in multiple trades at $39.590–$40.360 (footnote F2).
- 646 shares — weighted avg $37.82; executed in multiple trades at $37.490–$38.080 (footnote F3).
- 171 shares — weighted avg $38.61; executed in multiple trades at $38.520–$38.885 (footnote F4).
- Total proceeds: ~$158,757.
- Plan/authorization: Transactions were made pursuant to a Rule 10b5-1 plan adopted May 8, 2025 (footnote F1).
- Holdings: The filing references multiple trust holdings associated with Maetzold (footnotes F5–F13). The filing excerpt does not state the total shares owned after these transactions.
- Timeliness: Form 4 was filed Feb 5, 2026; the filing appears timely (no late-filing flag).
Context
Sales under a Rule 10b5-1 plan are prearranged and often scheduled in advance, which can indicate routine disposition rather than a real-time view on the company. For retail investors, purchases tend to carry more direct informational weight; these scheduled sales are a common way for insiders to diversify or meet liquidity needs.
Insider Transaction Report
Form 4
MAETZOLD DEREK J
DirectorPres. & Chief Exec. Officer
Transactions
- Sale
Common Stock
[F1][F2]2026-02-03$39.91/sh−3,200$127,722→ 84,515 total - Sale
Common Stock
[F1][F3]2026-02-04$37.82/sh−646$24,433→ 83,869 total - Sale
Common Stock
[F1][F4]2026-02-04$38.61/sh−171$6,602→ 83,698 total
Holdings
- 52,923(indirect: By Trust)
Common Stock
[F5] - 44,986(indirect: By Trust)
Common Stock
[F6] - 3,618(indirect: By Trust)
Common Stock
[F7] - 3,615(indirect: By Trust)
Common Stock
[F8] - 3,615(indirect: By Trust)
Common Stock
[F9] - 3,615(indirect: By Trust)
Common Stock
[F10] - 85,959(indirect: By Trust)
Common Stock
[F11] - 18,718(indirect: By Trust)
Common Stock
[F12] - 44,323(indirect: By Trust)
Common Stock
[F13]
Footnotes (13)
- [F1]These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on May 8, 2025.
- [F10]Held by The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- [F11]Held by DJM Grantor Retained Annuity Trust No. 5 of which the Reporting Person is the trustee and beneficiary.
- [F12]Held by DJM Grantor Retained Annuity Trust No. 6 of which the Reporting Person is the trustee and the beneficiaries are The Maetzold 2018 Remainder Trust FBO John Derek Maetzold, The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk, The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold and The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold.
- [F13]Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
- [F2]This transaction was executed in multiple trades at prices ranging from $39.590 to $40.360, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
- [F3]This transaction was executed in multiple trades at prices ranging from $37.490 to $38.080, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
- [F4]This transaction was executed in multiple trades at prices ranging from $38.520 to $38.885, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
- [F5]Held by The Maetzold Descendants 2020 Trust of which the Reporting Person's spouse is the trustee and the Reporting Person's spouse and their children are beneficiaries.
- [F6]Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.
- [F7]Held by The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk of which the Reporting Person is the trustee and his child is the beneficiary.
- [F8]Held by The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- [F9]Held by The Maetzold 2018 Remainder Trust FBO John Derek Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
Signature
/s/ Frank Stokes, Attorney-in-fact|2026-02-05