Castle Biosciences (CSTL) CEO sells 4,017 shares in Rule 10b5-1 trade
Filing Impact
Filing Sentiment
Form Type
4
Rhea-AI Filing Summary
Castle Biosciences Inc.’s President and Chief Executive Officer, Derek J. Maetzold, reported a planned sale of common stock under a pre-established Rule 10b5-1 trading plan. On January 20, 2026, he sold 4,017 shares of common stock at a weighted-average price of $40.013 per share in multiple trades within a disclosed price range.
Following this sale, Maetzold directly holds 87,715 shares of Castle Biosciences common stock, and additional shares are held indirectly through various family and grantor retained annuity trusts for which he or his spouse serves as trustee or beneficiary. The filing reflects an orderly, pre-planned diversification step rather than an ad hoc transaction.
Positive
- None.
Negative
- None.
Insider Trade Summary
Net Seller: 4,017 shares ($160,732)
Net Sell
10 txns
Insider
MAETZOLD DEREK J
Role
Pres. & Chief Exec. Officer
Sold
4,017 shs ($161K)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 4,017 | $40.013 | $161K |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
Holdings After Transaction:
Common Stock — 87,715 shares (Direct);
Common Stock — 52,923 shares (Indirect, By The Maetzold Descendants 2020 Trust)
Footnotes (1)
- These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on May 8, 2025. This transaction was executed in multiple trades at prices ranging from $39.695 to 40.250, 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. 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. Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries. 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. 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. 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. 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. Held by DJM Grantor Retained Annuity Trust No. 5 of which the Reporting Person is the trustee and beneficiary. 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. Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
FAQ
What insider transaction did CSTL report in this Form 4?
The Form 4 reports that Derek J. Maetzold, President and Chief Executive Officer of Castle Biosciences Inc. (CSTL), sold 4,017 shares of common stock on January 20, 2026 at a weighted-average price of $40.013 per share.
Was the CSTL CEO’s stock sale made under a Rule 10b5-1 plan?
Yes. The filing states that the transactions were made pursuant to a Rule 10b5-1 trading plan adopted by Derek J. Maetzold on May 8, 2025, indicating the sales were pre-arranged rather than discretionary.
Does this Form 4 report any CSTL derivative securities transactions?
No. The section for derivative securities shows no reported acquisitions or dispositions; the filing only details transactions and holdings in Castle Biosciences common stock.