[Form 4] Castle Biosciences, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Kristen M. Oelschlager, Chief Operating Officer of Castle Biosciences, Inc. (CSTL), reported the sale of 18,007 shares of the issuer's common stock on 08/27/2025. The sales were executed in multiple trades at prices ranging from $21.24 to $21.94, with a reported weighted-average sale price of $21.69. Following the reported disposition, Oelschlager beneficially owned 153,793 shares, held directly. The Form 4 was signed by an attorney-in-fact, Frank Stokes, on 08/29/2025. The filer affirms availability to provide trade-level price and share details upon request.

Insights

Securities Analyst

TL;DR: Officer sold a modest block of shares; ownership remains material but no other disclosures indicate company-impacting events.

The reported sale of 18,007 shares at a weighted-average price of $21.69 reduced the reporting officer's direct stake to 153,793 shares. This is a routine Section 16 disclosure showing an executive liquidity event rather than a change in control or compensation grant. The Form 4 discloses execution across multiple trades and offers to provide granular trade details on request, which supports transparency. Absent additional company disclosures, this filing alone is informational and carries limited standalone market impact.

Corporate Governance Expert

TL;DR: Transaction is a standard insider sale reported under Section 16; governance procedures appear followed via attorney-in-fact filing.

The filing identifies the reporting person as an officer and indicates the Form 4 was filed by a single reporting person and signed by an attorney-in-fact. The explanation notes multiple trade executions and a weighted-average price; the willingness to provide full trade-level details aligns with compliance norms. There is no indication of trading pursuant to a Rule 10b5-1 plan in the form text provided.

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).

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^*

Oelschlager Kristen M

(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 Operating Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/27/2025

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	08/27/2025		S		18,007	D	$21.69(1)	153,793	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 $21.24 to $21.94, 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	08/29/2025
	** 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 did Kristen M. Oelschlager report on Form 4 for CSTL?

She reported the sale of 18,007 common shares on 08/27/2025 at a weighted-average price of $21.69, leaving her with 153,793 shares beneficially owned.

When were the CSTL shares sold and at what prices?

Sales occurred on 08/27/2025 in multiple trades at prices ranging from $21.24 to $21.94; the weighted-average sale price reported is $21.69.

Does the Form 4 indicate the sale was part of a 10b5-1 trading plan?

No. The provided Form 4 text does not indicate the transaction was made pursuant to a Rule 10b5-1(c) plan.

How many shares does Oelschlager own after the sale?

153,793 shares are reported as beneficially owned following the disposition.

Who signed the Form 4 filing for the reporting person?

Frank Stokes, Attorney-in-fact, signed the Form 4 on 08/29/2025.