Stokes Frank 4

4 · CASTLE BIOSCIENCES INC · Filed Mar 5, 2026

Insider Transaction Report

Form 4

Period: 2026-03-03

CASTLE BIOSCIENCES INCCSTL

Stokes Frank

Chief Financial Officer

Transactions

Sale
Common Stock
[F1][F2][F3]
2026-03-03$27.32/sh−5,300$144,796→ 54,183 total
Sale
Common Stock
[F1][F4]
2026-03-03$27.81/sh−1,700$47,277→ 52,483 total
Tax Payment
Common Stock
[F5]
2026-03-03$27.57/sh−3,611$99,555→ 48,872 total
Exercise/Conversion
Common Stock
[F6]
2026-03-04+24,146→ 73,018 total
Tax Payment
Common Stock
2026-03-04$28.17/sh−10,732$302,320→ 62,286 total
Exercise/Conversion
Common Stock
2026-03-04$3.38/sh+3,800$12,844→ 66,086 total
Award
Restricted Stock Units
[F6][F7]
2026-03-03+48,367→ 48,367 total
→ Common Stock (48,367 underlying)
Exercise/Conversion
Restricted Stock Units
[F6][F8]
2026-03-04−12,186→ 24,372 total
→ Common Stock (12,186 underlying)
Exercise/Conversion
Restricted Stock Units
[F6][F9]
2026-03-04−11,960→ 35,878 total
→ Common Stock (11,960 underlying)
Exercise/Conversion
Stock option (right to buy)
[F10]
2026-03-04−3,800→ 14,912 total
Exercise: $3.38Exp: 2029-03-12→ Common Stock (3,800 underlying)

Footnotes (10)

[F1]The transaction on this Form 4 was made pursuant to a Rule 10b5-1 plan adopted by Frank Stokes on November 13, 2025.
[F10]The shares subject to the option are fully vested.
[F2]This transaction was executed in multiple trades at prices ranging from $26.70 to $27.67, 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]Includes 1,033 shares acquired on February 27, 2026, under the Issuer's employee stock purchase plan.
[F4]This transaction was executed in multiple trades at prices ranging from $27.72 to $27.97, 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]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.
[F6]Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.
[F7]The RSU's vest in four equal annual installments beginning on March 03, 2027.
[F8]On March 4, 2024, the Reporting Person was granted 48,744 RSUs which vest in four equal installments beginning on March 4, 2025.
[F9]On March 4, 2025, the Reporting Person was granted 47,838 RSUs which vest in four equal installments beginning on March 4, 2026.

Signature

/s/ Frank Stokes, Attorney-in-fact|2025-03-05

Documents

1 file

4
wk-form4_1772748515.xmlPrimary
FORM 4