| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| MAETZOLD DEREK J | Pres. & Chief Exec. Officer, Director | C/O CASTLE BIOSCIENCES, INC., 1500 W. PARKWOOD AVE SUITE 400, FRIENDSWOOD | /s/ Frank Stokes, Attorney-in-fact | 05 Feb 2026 | 0001239501 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | CSTL | Common Stock | Sale | $127,722 | -3,200 | -3.6% | $39.91 | 84,515 | 03 Feb 2026 | Direct | F1, F2 |
| transaction | CSTL | Common Stock | Sale | $24,433 | -646 | -0.76% | $37.82 | 83,869 | 04 Feb 2026 | Direct | F1, F3 |
| transaction | CSTL | Common Stock | Sale | $6,602 | -171 | -0.2% | $38.61 | 83,698 | 04 Feb 2026 | Direct | F1, F4 |
| holding | CSTL | Common Stock | 52,923 | 03 Feb 2026 | By The Maetzold Descendants 2020 Trust | F5 | |||||
| holding | CSTL | Common Stock | 44,986 | 03 Feb 2026 | By Derek Maetzold 2020 Irrevocable Trust | F6 | |||||
| holding | CSTL | Common Stock | 3,618 | 03 Feb 2026 | By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk | F7 | |||||
| holding | CSTL | Common Stock | 3,615 | 03 Feb 2026 | By The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold | F8 | |||||
| holding | CSTL | Common Stock | 3,615 | 03 Feb 2026 | By The Maetzold 2018 Remainder Trust FBO John Derek Maetzold | F9 | |||||
| holding | CSTL | Common Stock | 3,615 | 03 Feb 2026 | By The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold | F10 | |||||
| holding | CSTL | Common Stock | 85,959 | 03 Feb 2026 | By DJM Grantor Retained Annuity Trust No. 5 | F11 | |||||
| holding | CSTL | Common Stock | 18,718 | 03 Feb 2026 | By DJM Grantor Retained Annuity Trust No. 6 | F12 | |||||
| holding | CSTL | Common Stock | 44,323 | 03 Feb 2026 | By DJM Grantor Retained Annuity Trust No. 7 | F13 |
Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.
Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).
| Id | Content |
|---|---|
| F1 | These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on May 8, 2025. |
| 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. |
| 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. |