CASTLE BIOSCIENCES INC — Director's Dealing 2021

May 13, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CASTLE BIOSCIENCES INC (CSTL)
CIK: 0001447362
Period of Report: 2021-05-11

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-11	Common Stock	S	379	$51.628	Disposed	565639	Direct
2021-05-11	Common Stock	S	1157	$52.603	Disposed	564482	Direct
2021-05-11	Common Stock	S	1100	$53.685	Disposed	563382	Direct
2021-05-11	Common Stock	S	697	$54.404	Disposed	562685	Direct
2021-05-12	Common Stock	S	2533	$51.935	Disposed	560152	Direct
2021-05-12	Common Stock	S	800	$52.876	Disposed	559352	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 $51.110 to $52.070, 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 $52.185 to $53.180, 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 $53.210 to $54.180, 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 $54.240 to $54.540, 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: This transaction was executed in multiple trades at prices ranging from $51.570 to $52.460, 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.

F7: This transaction was executed in multiple trades at prices ranging from $52.570 to $53.350, 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.

F8: Held by DJM Grantor Retained Annuity Trust No. 1 of which the Reporting Person is the trustee and beneficiary.

F9: 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.

F10: Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.