[Form 4] CASTLE BIOSCIENCES INC Insider Trading Activity

Rhea-AI Filing Summary

Castle Biosciences (CSTL) reported insider activity by its Chief Commercial Officer. On 11/20/2025, the officer exercised a stock option to buy 4,693 shares of common stock at $3.38 per share and on the same day sold 4,693 shares in open-market transactions at a weighted-average price of $35.58, with individual trades ranging from $35.40 to $35.85. These trades were carried out under a Rule 10b5-1 trading plan adopted on September 11, 2024.

After the transactions and a 68-share reconciliation adjustment, the officer beneficially owns 84,595 shares directly and 2,230 shares indirectly through a family revocable trust. The officer also holds 11,210 fully vested stock options with a $3.38 exercise price expiring on March 12, 2029.

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

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

X

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)
11/20/2025

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	11/20/2025		M(1)		4,693	A	$3.38	89,288(2)	D
Common Stock	11/20/2025		S(1)		4,693	D	$35.58(3)	84,595(2)	D
Common Stock								2,230	I	By Tobin W and Susan M Juvenal Family Revocable Trust(4)

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
Stock option (right to buy)	$3.38	11/20/2025		M(1)			4,693	(5)	03/12/2029	Common Stock	4,693	$0	11,210	D

Explanation of Responses:

1. This transaction was made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on September 11, 2024.

2. Reflects an adjustment of 68 shares to the number of shares beneficially owned following a reconciliation of the Reporting Person's records.

3. This transaction was executed in multiple trades at prices ranging from $35.40 to $35.85, 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.

4. Held by Tobin W and Susan M Juvenal Family Revocable Trust of which the Reporting Person and his spouse are the trustees and the Reporting Person, his spouse and their children are the beneficiaries.

5. The shares subject to the option are fully vested.

Remarks:

	/s/ Frank Stokes, Attorney-in-fact	11/24/2025
	** 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 the CSTL Chief Commercial Officer report?

The Chief Commercial Officer exercised a stock option for 4,693 CSTL shares at $3.38 per share and sold 4,693 shares on 11/20/2025 in the open market.

At what prices were the CSTL shares sold in this Form 4 filing?

The shares were sold at a weighted-average price of $35.58 per share, with individual trades executed between $35.40 and $35.85 on 11/20/2025.

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

Following the reported transactions and a 68-share adjustment, the insider beneficially owns 84,595 CSTL shares directly and 2,230 shares indirectly through a family revocable trust.

What stock options does the CSTL insider still hold after this Form 4?

The insider continues to hold 11,210 fully vested stock options with an exercise price of $3.38 per share, expiring on March 12, 2029.

Was the Castle Biosciences insider trade made under a Rule 10b5-1 plan?

Yes. The filing states that the transaction was made under a Rule 10b5-1 trading plan that the reporting person adopted on September 11, 2024.

What is the relationship of the reporting person to Castle Biosciences (CSTL)?

The reporting person serves as an officer of Castle Biosciences, holding the title of Chief Commercial Officer.

How is the family trust related to the CSTL insider’s holdings?

2,230 CSTL shares are held by the Tobin W and Susan M Juvenal Family Revocable Trust, for which the insider and spouse are trustees and beneficiaries with their children.