CASTLE BIOSCIENCES INC — Director's Dealing 2021

May 14, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CASTLE BIOSCIENCES INC (CSTL)
CIK: 0001447362
Period of Report: 2021-05-13

Reporting Person: MAETZOLD DEREK J (Director, Pres. & Chief Exec. Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-13	Common Stock	S	886	$49.748	Disposed	558466	Direct
2021-05-13	Common Stock	S	1547	$50.508	Disposed	556919	Direct
2021-05-13	Common Stock	S	600	$51.638	Disposed	556319	Direct
2021-05-13	Common Stock	S	300	$52.747	Disposed	556019	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	156460	Indirect
Common Stock	179300	Indirect
Common Stock	166700	Indirect

Footnotes

F1: These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on December 11, 2020.

F2: This transaction was executed in multiple trades at prices ranging from $49.260 to $50.250, 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 $50.285 to $51.215, 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 $51.320 to $52.150, 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: This transaction was executed in multiple trades at prices ranging from $52.500 to $52.940, 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.

F6: Held by DJM Grantor Retained Annuity Trust No. 1 of which the Reporting Person is the trustee and beneficiary.

F7: 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.

F8: Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.