SEC Form 4 · accession 0001628280-26-044019
CASTLE BIOSCIENCES INC · CSTL
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Derek J Maetzold
Officer — Pres. & Chief Exec. Officer · Director
Period of report
Jun 15, 2026
Accepted (ET)
Jun 17, 2026 · 5:39 pm EDT
Rule 10b5-1 plan
yes — trade under a plan
Issuer CIK
0001447362
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common Stock | Jun 15, 2026 | M | 550 | $2.39 | A | 22,029 | D | |
| Common StockF2 | Jun 15, 2026 | S | 550 | $20.66 | D | 21,479 | D | |
| Common StockF2,F3 | Jun 15, 2026 | S | 1,357 | $20.66 | D | 42,067 | I | By The Maetzold Descendants 2020 Trust |
| Common StockF2,F4 | Jun 15, 2026 | S | 1,153 | $20.66 | D | 35,755 | I | By Derek Maetzold 2020 Irrevocable Trust |
| Common StockF2,F5,F6 | Jun 15, 2026 | S | 278 | $20.66 | D | 12,646 | I | By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk |
| Common StockF2,F5,F7 | Jun 15, 2026 | S | 278 | $20.66 | D | 12,646 | I | By The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold |
| Common StockF2,F5,F8 | Jun 15, 2026 | S | 278 | $20.66 | D | 12,646 | I | By The Maetzold 2018 Remainder Trust FBO John Derek Maetzold |
| Common StockF2,F5,F9 | Jun 15, 2026 | S | 278 | $20.66 | D | 12,646 | I | By The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold |
| Common StockF10 | holding | — | — | — | 18,718 | I | By DJM Grantor Retained Annuity Trust No. 6 | |
| Common StockF11 | holding | — | — | — | 44,323 | I | By DJM Grantor Retained Annuity Trust No. 7 | |
| Common StockF12 | holding | — | — | — | 40,935 | I | By DJM Grantor Retained Annuity Trust No. 8 |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Stock option (right to buy)F13 | $2.39 | Jun 15, 2026 | M | 550 | D | — | May 9, 2028 | Common Stock | 550 | 91,881 | D |
Explanation of responses
- F1These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on December 3, 2025.
- F10Held 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.
- F11Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
- F12Held by DJM Grantor Retained Annuity Trust No. 8 of which the Reporting Person is the trustee and beneficiary. On June 10, 2026, 40,935 shares of common stock were transferred from DJM Grantor Annuity Trust No. 5 to the Reporting Person's direct holdings, and subsequently transferred from the Reporting Person's direct holdings to DJM Grantor Retained Annuity Trust No. 8.
- F13The shares subject to the option are fully vested.
- F2This transaction was executed in multiple trades at prices ranging from $20.44 to $20.98, 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.
- F3Held 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.
- F4Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.
- F5Reflects the transfers on June 10, 2026, of 45,024 shares of common stock from DJM Grantor Annuity Trust No. 5, of which, 11,256 transferred to The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk, 11,256 transferred to The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold, 11,256 transferred to The Maetzold 2018 Remainder Trust FBO John Derek Maetzold and 11,256 transferred to The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold. The remaining 40,935 shares of common stock held by DJM Grantor Annuity Trust No. 5 were transferred as described in footnote 12, after which DJM Grantor Annuity Trust No. 5 holds no remaining shares of common stock.
- F6Held by The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk of which the Reporting Person is the trustee and his child is the beneficiary.
- F7Held by The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- F8Held by The Maetzold 2018 Remainder Trust FBO John Derek Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.
- F9Held by The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.