CSTL holder plans sale of 24,908 shares

A holder of CSTL common stock filed a notice of intent to sell up to 24,908 shares through Morgan Stanley Smith Barney LLC Executive Financial Services on 08/14/2026, with the shares listed on NASDAQ.

Rhea-AI Filing Summary

A holder of CSTL common stock filed a notice of intent to sell up to 24,908 shares through Morgan Stanley Smith Barney LLC Executive Financial Services on 08/14/2026, with the shares listed on NASDAQ. The shares have an indicated aggregate market value of $741,493.72. They stem from restricted stock originally acquired from the issuer on several dates, including 8,082 shares on 12/09/2025, 6,644 shares on 03/04/2026, 3,412 shares on 12/10/2025, and 6,770 shares on 03/04/2026, all for cash. Shares outstanding were 30,549,507; this is a baseline figure, not the amount being sold.

Key Figures

Shares planned for sale: 24,908 shares Aggregate market value: $741,493.72 Shares outstanding: 30,549,507 shares +3 more

6 metrics

Shares planned for sale 24,908 shares Maximum CSTL common shares covered by the Form 144 notice

Aggregate market value $741,493.72 Indicated value of the 24,908 CSTL shares planned for sale

Shares outstanding 30,549,507 shares Total CSTL shares outstanding used as a baseline in the filing

Planned sale date 08/14/2026 Date on which the CSTL shares are expected to be sold

Restricted stock lot 8,082 shares Restricted stock acquired on 12/09/2025 for cash from the issuer

Restricted stock lot 6,644 shares Restricted stock acquired on 03/04/2026 for cash from the issuer

Key Terms

Form 144, Restricted Stock, NASDAQ, aggregate market value

4 terms

Form 144 regulatory

"Filer Information | | | 144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Restricted Stock financial

"Common | 12/09/2025 | Restricted Stock | Issuer |"

Shares granted to an individual that carry limits on transfer or sale until certain conditions are met, such as staying with the company for a set time or hitting performance targets. Think of them as a locked gift that gradually opens; for investors they matter because they affect how many shares may enter the market later, signal management incentives and potential dilution, and reveal confidence in future company performance.

NASDAQ market

"30549507 | 08/14/2026 | NASDAQ"

The Nasdaq is a stock exchange where many companies' shares are bought and sold, functioning much like a marketplace for investments. It matters to investors because it provides a platform to buy and sell ownership stakes in companies, helping them track the value of those companies and make informed decisions. As one of the largest and most technology-focused markets, it also reflects trends and developments in the business world.

aggregate market value financial

"24908 | 741493.72 | 30549507 | 08/14/2026"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the CSTL Form 144 filing disclose?

The Form 144 for CSTL discloses a planned sale of up to 24,908 common shares on NASDAQ, with an indicated aggregate market value of $741,493.72 through Morgan Stanley Smith Barney LLC.

How many CSTL shares are planned for sale and at what value?

The filing covers a proposed sale of 24,908 CSTL common shares with an indicated aggregate market value of $741,493.72. This represents only a portion of the company’s 30,549,507 shares outstanding.

When is the planned sale of CSTL shares expected to occur?

The Form 144 indicates an expected sale date of 08/14/2026 for the 24,908 CSTL common shares. Actual sales can vary based on market conditions and trading decisions within the disclosed framework.

What is the source of the CSTL shares being sold in this Form 144?

The 24,908 CSTL shares come from restricted stock acquired from the issuer on several dates, including 8,082, 6,644, 3,412, and 6,770 shares, all purchased for cash consideration.

Which broker is handling the planned CSTL share sale?

The planned sale of 24,908 CSTL common shares will be handled by Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, 8th Floor, New York, NY 10004.

How does the planned CSTL share sale compare to total shares outstanding?

The planned sale involves 24,908 CSTL shares versus 30,549,507 shares outstanding. This gives investors a sense of scale, with the planned sale covering only a small portion of total shares.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 08/14/2026 - 06:50 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001782815
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	CASTLE BIOSCIENCES, INC.
SEC File Number	001-38984
Address of Issuer	1500 W. Parkwood Ave, Suite 400 Friendswood TEXAS 77546
Phone	866-788-9007
Name of Person for Whose Account the Securities are To Be Sold	FRANKLIN M. STOKES
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	24908	741493.72	30549507	08/14/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	12/09/2025	Restricted Stock	Issuer			8082	12/09/2025	Cash
Common	03/04/2026	Restricted Stock	Issuer			6644	03/04/2026	Cash
Common	12/10/2025	Restricted Stock	Issuer			3412	12/10/2025	Cash
Common	03/04/2026	Restricted Stock	Issuer			6770	03/04/2026	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Nothing to Report

144: Remarks and Signature

Remarks
Date of Notice	08/14/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Franklin Stokes
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)