Castle Biosciences (NASDAQ: CSTL) CCO reports RSU settlements and share disposals

Rhea-AI Filing Summary

Castle Biosciences' Chief Commercial Officer reported equity transactions involving restricted stock units and common stock. On December 9, 2025 and December 10, 2025, the reporting person acquired 15,961 and 6,170 shares of common stock coded "M" in connection with restricted stock units, and disposed of 6,441 and 2,490 shares coded "F" at prices of $38.25 and $38.02 per share.

After these transactions, the officer beneficially owned 100,025 shares of Castle Biosciences common stock directly. The filing also shows 15,961 restricted stock units outstanding from a grant made on December 9, 2022 that vests in four equal installments beginning on December 9, 2023, and notes that 24,679 restricted stock units granted on December 10, 2021 vest in four equal installments beginning on December 10, 2022. The ownership total includes 2,230 shares that were previously held by a family revocable trust and were distributed to the reporting person on February 5, 2025.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Juvenal Tobin W

(Last) (First) (Middle)

C/O CASTLE BIOSCIENCES, INC.

505 S FRIENDSWOOD DRIVE, SUITE 401

(Street)

FRIENDSWOOD TX 77546

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CASTLE BIOSCIENCES INC [ CSTL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Commercial Officer

3. Date of Earliest Transaction (Month/Day/Year)
12/09/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	12/09/2025		M		15,961	A	(1)	102,786(2)	D
Common Stock	12/09/2025		F		6,441	D	$38.25	96,345	D
Common Stock	12/10/2025		M		6,170	A	(1)	102,515	D
Common Stock	12/10/2025		F		2,490	D	$38.02	100,025	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(1)	12/09/2025		M			15,961	(3)	(3)	Common Stock	15,961	$0	15,961	D
Restricted Stock Units	(1)	12/10/2025		M			6,170	(4)	(4)	Common Stock	6,170	$0	0	D

Explanation of Responses:

1. Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.

2. The amount includes 2,230 shares previously held by the Tobin W and Susan M Juvenal Family Revocable Trust, which were distributed to the Reporting Person on February 5, 2025, and are now owned directly.

3. On December 9, 2022, the Reporting Person was granted 63,844 RSUs which vest in four equal installments beginning on December 9, 2023.

4. On December 10, 2021, the Reporting Person was granted 24,679 RSUs which vest in four equal installments beginning on December 10, 2022.

Remarks:

	/s/ Frank Stokes, Attorney-in-fact	12/11/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What insider activity did Castle Biosciences (CSTL) report in this Form 4?

The Form 4 shows Castle Biosciences' Chief Commercial Officer acquiring 15,961 and 6,170 shares of common stock coded "M" in connection with restricted stock units on December 9 and 10, 2025, and disposing of 6,441 and 2,490 shares coded "F" at $38.25 and $38.02 per share.

How many Castle Biosciences (CSTL) shares does the reporting person own after these transactions?

Following the reported transactions, the Chief Commercial Officer beneficially owned 100,025 shares of Castle Biosciences common stock directly.

What restricted stock unit (RSU) grants are involved for the Castle Biosciences (CSTL) officer?

The filing references a grant of 63,844 RSUs made on December 9, 2022 that vests in four equal installments beginning on December 9, 2023, and a grant of 24,679 RSUs made on December 10, 2021 that vests in four equal installments beginning on December 10, 2022.

How many restricted stock units remain outstanding for the Castle Biosciences (CSTL) officer?

After the reported RSU-related transactions, the filing shows 15,961 restricted stock units beneficially owned, tied to the grant made on December 9, 2022.

What does each RSU represent in this Castle Biosciences (CSTL) filing?

Each Restricted Stock Unit ("RSU") reported in the filing represents the right to receive one share of Castle Biosciences' common stock.

Were any Castle Biosciences (CSTL) shares moved from a family trust to the officer?

Yes. The amount of common stock beneficially owned includes 2,230 shares that were previously held by the Tobin W and Susan M Juvenal Family Revocable Trust and were distributed to the reporting person on February 5, 2025.