Dimensional Fund Advisors discloses 5.1% stake in Castle Biosciences (CSTL)

Rhea-AI Filing Summary

Dimensional Fund Advisors LP reported beneficial ownership of 1,474,089 shares of Castle Biosciences Inc common stock, representing 5.1% of the class. The filing states these shares are owned by investment funds advised or sub‑advised by Dimensional and that Dimensional disclaims beneficial ownership while reporting sole voting power over 1,447,712 shares and sole dispositive power over 1,474,089.

The Schedule 13G indicates the position is held in the ordinary course of business and not to influence control of the issuer. The filing was signed by Dimensional's Global Chief Compliance Officer on 10/09/2025.

Positive

• Material disclosure of 1,474,089 shares ( 5.1% ) provides transparency to investors
• Clear certification that the position is held in the ordinary course of business and not to influence control

Negative

• Dimensional disclaims beneficial ownership while reporting voting/dispositive power, which may limit clarity on ultimate economic ownership
• Passive status (Schedule 13G) means no stated engagement with issuer governance despite a >5% stake

Insights

Institutional Ownership Analyst

Dimensional holds a passive but material 5.1% stake via managed funds.

The position of 1,474,089 shares equals a modest, reportable stake that meets the >5% disclosure threshold and is reported on Schedule 13G, which typically signals a passive investment rather than an intent to change control.

This holding gives Dimensional sole voting power over 1,447,712 shares while it disclaims beneficial ownership because the securities are owned by the Funds it advises. Monitor any future amendments or Schedule 13D filings for changes in intent or increased ownership.

Compliance & Regulatory Specialist

Filing reflects standard adviser reporting and compliance certification.

The form identifies Dimensional as an investment adviser and contains the certification that the shares are held in the ordinary course of business and not to influence issuer control. The signature by the Global Chief Compliance Officer completes the required attestation.

Regulatory items to watch include any shift from Schedule 13G to Schedule 13D or material changes in voting/dispositive power; the current filing documents the passive status as of 10/09/2025.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Castle Biosciences Inc

(Name of Issuer)

Common Stock

(Title of Class of Securities)

14843C105

(CUSIP Number)

09/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 14843C105

1

Names of Reporting Persons

Dimensional Fund Advisors LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 1,447,712.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 1,474,089.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,474,089.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Castle Biosciences Inc
(b)	Address of issuer's principal executive offices: 505 S Friendswood Drive, Suite 401, Friendswood, TX 77546
Item 2.
(a)	Name of person filing: Dimensional Fund Advisors LP
(b)	Address or principal business office or, if none, residence: 6300 Bee Cave Road, Building One, Austin, TX 78746
(c)	Citizenship: Delaware Limited Partnership
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 14843C105
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 1,474,089 ** see Note 1 ** ** Note 1 ** Dimensional Fund Advisors LP, an investment adviser registered under Section 203 of the Investment Advisors Act of 1940, furnishes investment advice to four investment companies registered under the Investment Company Act of 1940, and serves as investment manager or sub-adviser to certain other commingled funds, group trusts and separate accounts (such investment companies, trusts and accounts, collectively referred to as the "Funds"). In certain cases, subsidiaries of Dimensional Fund Advisors LP may act as an adviser or sub-adviser to certain Funds. In its role as investment advisor, sub-adviser and/or manager, Dimensional Fund Advisors LP or its subsidiaries (collectively, "Dimensional") may possess voting and/or investment power over the securities of the Issuer that are owned by the Funds, and may be deemed to be the beneficial owner of the shares of the Issuer held by the Funds. However, all securities reported in this schedule are owned by the Funds. Dimensional disclaims beneficial ownership of such securities. In addition, the filing of this Schedule 13G shall not be construed as an admission that the reporting person or any of its affiliates is the beneficial owner of any securities covered by this Schedule 13G for any other purposes than Section 13(d) of the Securities Exchange Act of 1934.
(b)	Percent of class: 5.1 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 1,447,712** see Note 1 **
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 1,474,089** see Note 1 **
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Funds described in Note 1 above have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of the securities held in their respective accounts. To the knowledge of Dimensional, the interest of any one such Fund does not exceed 5% of the class of securities. Dimensional Fund Advisors LP disclaims beneficial ownership of all such securities.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dimensional Fund Advisors LP

Signature:	Selwyn Notelovitz
Name/Title:	Global Chief Compliance Officer
Date:	10/09/2025

FAQ

What stake does Dimensional Fund Advisors hold in Castle Biosciences (CSTL)?

Dimensional reports beneficial ownership of 1,474,089 shares, representing 5.1% of the common stock.

Does Dimensional have voting power over the CSTL shares?

Yes. The filing reports sole voting power over 1,447,712 shares and sole dispositive power over 1,474,089 shares.

Are the shares owned directly by Dimensional Fund Advisors?

No. The shares are owned by funds advised or sub‑advised by Dimensional; Dimensional disclaims direct beneficial ownership.

Was this position reported as passive or active?

The position is reported on Schedule 13G with a certification that the shares are held in the ordinary course of business and not to influence issuer control, indicating passive intent.

When was the Schedule 13G signed?

The filing was signed by the Global Chief Compliance Officer on 10/09/2025.