Castle Biosciences (CSTL) CCO receives 9,207 PSUs and 9,207 shares

Rhea-AI Filing Summary

Castle Biosciences reported that Chief Commercial Officer Juvenal Tobin received common stock as performance-based compensation. On January 12, 2026, 9,207 Performance-Based Stock Units (PSUs) from a grant made on March 4, 2024 vested after the board certified that certain performance criteria were met.

Each PSU converts into one share of Castle Biosciences common stock, so 9,207 shares of common stock were acquired at a price of $0 per share. Following this transaction, Tobin beneficially owned 96,032 shares of common stock directly, and 9,207 PSUs remain outstanding, which will vest only if additional milestones are achieved.

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)
01/12/2026

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	01/12/2026		A		9,207(1)	A	$0	96,032	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
Performance-Based Stock Unit	(2)	01/12/2026		A		9,207		(2)	(2)	Common Stock	9,207	$0	9,207	D

Explanation of Responses:

1. Represents 50% of the Performance-Based Stock Units ("PSUs") granted on March 4, 2024 ("2024 PSUs") that vested based on the satisfaction of certain performance criteria as certified by the board of directors of the Issuer on January 12, 2026.

2. Each PSU represents the right to receive one share of the Issuer's Common Stock. These PSUs represent the remaining 50% of the 2024 PSUs which will vest subject to the achievement of certain milestones.

	/s/ Frank Stokes, Attorney-in-Fact	01/14/2026
	** 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).
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FAQ

What insider transaction did Castle Biosciences (CSTL) disclose for January 12, 2026?

The company disclosed that Chief Commercial Officer Juvenal Tobin acquired 9,207 shares of Castle Biosciences common stock upon vesting of performance-based stock units on January 12, 2026.

What are the terms of the Performance-Based Stock Units reported by CSTL?

The filing states each Performance-Based Stock Unit (PSU) represents the right to receive one share of Castle Biosciences common stock. The reported 9,207 PSUs vested after performance criteria were certified as met, and another 9,207 PSUs will vest only upon achieving specified milestones.

How many Castle Biosciences shares does the CCO own after this Form 4 transaction?

After the reported transaction, Chief Commercial Officer Juvenal Tobin beneficially owned 96,032 shares of Castle Biosciences common stock directly, according to the filing.

Was any cash paid for the Castle Biosciences shares acquired in this Form 4?

No cash was paid for the acquisition described. The 9,207 common shares were acquired at a reported price of $0 per share upon vesting of performance-based stock units.

What portion of the 2024 PSUs for Castle Biosciences has vested so far?

The filing explains that the 9,207 vested PSUs represent 50% of the PSUs granted on March 4, 2024. The remaining 50% (another 9,207 PSUs) will vest only if certain milestones are achieved.

Is this Castle Biosciences (CSTL) Form 4 transaction direct or indirect ownership?

The Form 4 indicates that both the PSUs and the resulting common stock are held under direct (D) ownership by Juvenal Tobin.