Castle Biosciences CEO sells 19,300 shares
Castle Biosciences CEO Derek J. Maetzold reported open-market sales of 19,300 shares of Common Stock of CASTLE BIOSCIENCES INC.
Rhea-AI Filing Summary
Castle Biosciences CEO Derek J. Maetzold reported open-market sales of 19,300 shares of Common Stock of CASTLE BIOSCIENCES INC. He sold 18,650 shares at a weighted-average price of $25.93 on March 17, 2026 and 650 shares at $25.39 on March 18, 2026, leaving 21,479 shares held directly.
The filing notes these transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 3, 2025. Maetzold also reports indirect ownership of additional Common Stock through multiple family and grantor retained annuity trusts, including 51,566 shares held by The Maetzold Descendants 2020 Trust and other trusts where he serves as trustee or beneficiary.
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Insider Trade Summary 10b5-1
Net Seller: 19,300 shares
Net Sell
11 txns
Insider
MAETZOLD DEREK J
Role
Pres. & Chief Exec. Officer
Sold
19,300 shs ($500K)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 650 | $25.39 | $17K |
| Sale | Common Stock | 18,650 | $25.93 | $484K |
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Holdings After Transaction:
Common Stock — 21,479 shares (Direct);
Common Stock — 51,566 shares (Indirect, By The Maetzold Descendants 2020 Trust);
Common Stock — 43,826 shares (Indirect, By Derek Maetzold 2020 Irrevocable Trust);
Common Stock — 3,336 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk);
Common Stock — 3,336 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold);
Common Stock — 3,336 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO John Derek Maetzold);
Common Stock — 3,336 shares (Indirect, By The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold);
Common Stock — 85,959 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 5);
Common Stock — 18,718 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 6);
Common Stock — 44,323 shares (Indirect, By DJM Grantor Retained Annuity Trust No. 7)
Footnotes (12)
- F1. These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on December 3, 2025.
- F2. This transaction was executed in multiple trades at prices ranging from $25.66 to $26.27, 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 $25.26 to $25.48, 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. 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.
- F5. Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.
- F6. 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.
- F7. 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.
- F8. 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.
- F9. 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.
- F10. Held by DJM Grantor Retained Annuity Trust No. 5 of which the Reporting Person is the trustee and beneficiary.
- F11. 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.
- F12. Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What did CSTL CEO Derek Maetzold report in this Form 4 filing?
The Form 4 shows CEO Derek Maetzold sold 19,300 Castle Biosciences shares in open-market transactions under a Rule 10b5-1 plan, at weighted-average prices around $26, and now holds 21,479 shares directly plus additional indirect holdings through several family-related trusts.
Was the CSTL CEO’s stock sale done under a Rule 10b5-1 trading plan?
Yes. The filing states the transactions were made pursuant to a Rule 10b5-1 plan adopted by Derek Maetzold on December 3, 2025. Such pre-arranged plans automate trading and can indicate the timing was predetermined rather than based on short-term market developments.
Are the CSTL CEO’s reported transactions open-market sales or other types of transfers?
The two transactions with share amounts are coded “S” and described as open-market or private sales of Common Stock. Other entries in the filing reflect holding balances in various trusts, with no share amounts transacted and no buy or sell direction indicated for those records.
AI-generated analysis. How Rhea-AI works. Not financial advice.
