Kristen M. Oelschlager - 03 Mar 2026 Form 4 Insider Report for CASTLE BIOSCIENCES INC (CSTL)

Role
Chief Operating Officer
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, 17:16:56 UTC
Previous filing
14 Jan 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Oelschlager Kristen M Chief Operating Officer C/O CASTLE BIOSCIENCES, INC., 1500 W. PARKWOOD AVE SUITE 400, FRIENDSWOOD /s/ Frank Stokes, Attorney-in-fact 05 Mar 2025 0001856565

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction CSTL Common Stock Tax liability -2,427 -11% $27.57* 20,068 03 Mar 2026 Direct F1, F2
transaction CSTL Common Stock Options Exercise +25,771 +128% 45,839 04 Mar 2026 Direct F3
transaction CSTL Common Stock Tax liability -6,792 -15% $28.17* 39,047 04 Mar 2026 Direct
holding CSTL Common Stock 97,251 03 Mar 2026 The Fritz Shorter Trust F4

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 +48,367 $0.000000* 48,367 03 Mar 2026 Common Stock 48,367 Direct F3, F5
transaction CSTL Restricted Stock Units Options Exercise -13,811 -33% $0.000000* 27,621 04 Mar 2026 Common Stock 13,811 Direct F3, F6
transaction CSTL Restricted Stock Units Options Exercise -11,960 -25% $0.000000* 35,878 04 Mar 2026 Common Stock 11,960 Direct F3, F7
* 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 Includes 965 shares acquired on February 27, 2026, under the Issuer's employee stock purchase plan.
F3 Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.
F4 Held by the Fritz Shorter Trust of which the Reporting Person and her spouse are the trustees and beneficiaries.
F5 The RSU's vest in four equal annual installments beginning on March 03, 2027.
F6 On March 4, 2024, the Reporting Person was granted 55,243 RSUs which vest in four equal installments beginning on March 4, 2025.
F7 On March 4, 2025, the Reporting Person was granted 47,838 RSUs which vest in four equal installments beginning on March 4, 2026.