DEREK J. MAETZOLD - 03 Mar 2026 Form 4 Insider Report for CASTLE BIOSCIENCES INC (CSTL)

Role
Pres. & Chief Exec. Officer, Director
Signature
/s/ Frank Stokes, Attorney-in-fact
Issuer symbol
CSTL
Transactions as of
03 Mar 2026
Net transactions value
$0
Form type
4
Filing time
05 Mar 2026, 17:12:16 UTC
Previous filing
05 Feb 2026
SEC
View on sec.gov

Reporting Owners (1)

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 Mar 2025 0001239501

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction CSTL Common Stock Tax liability -19,043 -23% $27.57* 64,655 03 Mar 2026 Direct F1
transaction CSTL Common Stock Options Exercise +59,097 +91% 123,752 04 Mar 2026 Direct F2
transaction CSTL Common Stock Tax liability -17,931 -14% $28.17* 105,821 04 Mar 2026 Direct
holding CSTL Common Stock 52,923 03 Mar 2026 By The Maetzold Descendants 2020 Trust F3
holding CSTL Common Stock 44,986 03 Mar 2026 By Derek Maetzold 2020 Irrevocable Trust F4
holding CSTL Common Stock 3,618 03 Mar 2026 By The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk F5
holding CSTL Common Stock 3,615 03 Mar 2026 By The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold F6
holding CSTL Common Stock 3,615 03 Mar 2026 By The Maetzold 2018 Remainder Trust FBO John Derek Maetzold F7
holding CSTL Common Stock 3,615 03 Mar 2026 By The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold F8
holding CSTL Common Stock 85,959 03 Mar 2026 By DJM Grantor Retained Annuity Trust No. 5 F9
holding CSTL Common Stock 18,718 03 Mar 2026 By DJM Grantor Retained Annuity Trust No. 6 F10
holding CSTL Common Stock 44,323 03 Mar 2026 By DJM Grantor Retained Annuity Trust No. 7 F11

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction CSTL Restricted Stock Units Award +102,597 $0.000000* 102,597 03 Mar 2026 Common Stock 102,597 Direct F2, F12
transaction CSTL Restricted Stock Units Options Exercise -31,110 -33% $0.000000* 62,218 04 Mar 2026 Common Stock 31,110 Direct F2, F13
transaction CSTL Restricted Stock Units Options Exercise -27,987 -25% $0.000000* 83,961 04 Mar 2026 Common Stock 27,987 Direct F2, F14
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Reflects the withholding of shares of the Issuer's common stock to satisfy tax withholding obligations in connection with the delivery of vested performance stock units reported on January 12, 2026.
F2 Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.
F3 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.
F4 Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.
F5 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.
F6 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.
F7 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.
F8 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.
F9 Held by DJM Grantor Retained Annuity Trust No. 5 of which the Reporting Person is the trustee and beneficiary.
F10 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.
F11 Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.
F12 The RSU's vest in four equal annual installments beginning on March 03, 2027.
F13 On March 4, 2024, the Reporting Person was granted 124,437 RSUs which vest in four equal installments beginning on March 4, 2025.
F14 On March 4, 2025, the Reporting Person was granted 111,948 RSUs which vest in four equal installments beginning on March 4, 2026.