Castle Biosciences (CSTL) CCO reports sale of 13,200 shares

Rhea-AI Filing Summary

Castle Biosciences’ chief commercial officer reported selling 13,200 shares of the company’s common stock on 12/11/2025 at a weighted-average price of $37.48 per share. The transaction is disclosed as a sale of non-derivative securities on a Form 4 filing.

Following this sale, the officer directly beneficially owns 86,825 shares of Castle Biosciences common stock. The filing notes that the transaction was executed in multiple trades at prices ranging from $37.31 to $37.72 per share, with the reported price reflecting the weighted-average sale price.

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

OMB APPROVAL

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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)
12/11/2025

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	12/11/2025		S		13,200	D	$37.48(1)	86,825	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

Explanation of Responses:

1. This transaction was executed in multiple trades at prices ranging from $37.31 to $37.72, 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.

Remarks:

	/s/ Frank Stokes, Attorney-in-fact	12/15/2025
	** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Castle Biosciences (CSTL) report?

Castle Biosciences disclosed that its chief commercial officer sold 13,200 shares of the company’s common stock on 12/11/2025 at a weighted-average price of $37.48 per share.

Who executed the reported share sale at Castle Biosciences (CSTL)?

The shares were sold by a reporting person who serves as Castle Biosciences’ chief commercial officer, as indicated in the Form 4 relationship section.

How many Castle Biosciences (CSTL) shares does the insider own after the sale?

After the reported transaction, the chief commercial officer directly beneficially owns 86,825 shares of Castle Biosciences common stock.

At what prices were the Castle Biosciences (CSTL) shares sold?

The filing states the transaction was executed in multiple trades at prices ranging from $37.31 to $37.72 per share, with a weighted-average sale price of $37.48.

Was the Castle Biosciences (CSTL) share sale a single trade or multiple trades?

The Form 4 explains that the transaction was executed in multiple trades, and the disclosed price represents the weighted-average sale price across those trades.

What type of security did the Castle Biosciences (CSTL) insider sell?

The reporting person sold common stock, which is listed in Table I as a non-derivative security.