CSTL insider plans sale of 22,500 common shares

An affiliate of CSTL has filed to sell common stock through a broker-dealer.

Rhea-AI Filing Summary

An affiliate of CSTL has filed to sell common stock through a broker-dealer. The notice covers the potential sale of 22,500 shares of common stock, with an indicated aggregate market value of $630,000, to be sold through NASD on or after July 31, 2026.

The shares derive from multiple equity compensation grants, including Restricted Stock Units and Restricted Stock Awards acquired on dates such as December 10, 2021, February 28, 2022, August 9, 2024, December 9, 2024, and December 10, 2024, with individual grant sizes ranging from 494 to 12,074 shares.

Key Figures

Planned shares to be sold: 22,500 shares Aggregate market value: $630,000 Earliest sale date: 07/31/2026 +4 more

7 metrics

Planned shares to be sold 22,500 shares Common stock covered by the notice of proposed sale

Aggregate market value $630,000 Value associated with the 22,500 common shares

Earliest sale date 07/31/2026 Date tied to the proposed disposition of common shares

RSU grant 4,666 shares Restricted Stock Units acquired as compensation on 12/10/2024

RSU grant 1,323 shares Restricted Stock Units acquired as compensation on 12/10/2021

Restricted Stock Award 494 shares Restricted Stock Awards acquired as compensation on 02/28/2022

Largest RSU grant 12,074 shares Restricted Stock Units acquired as compensation on 12/09/2024

Key Terms

Form 144, Restricted Stock Units, Restricted Stock Awards, aggregate market value

4 terms

Form 144 regulatory

"144: Securities To Be Sold"

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 Units financial

"Acquired as compensation -- Restricted Stock Units"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Restricted Stock Awards financial

"Acquired as compensation -- Restricted Stock Awards"

Restricted stock awards are company shares given to employees or executives that cannot be sold or transferred until certain conditions — like staying with the company for a set time or meeting performance targets — are met, like a gift that is locked in a safe until rules are satisfied. Investors care because these awards tie management’s pay to company performance, can increase the number of shares outstanding when they become tradable (dilution), and may signal expected future selling pressure or commitment to long-term growth.

aggregate market value financial

"22500 | 630000 | 30329952 | 07/31/2026"

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 amount of CSTL common stock is covered by this Form 144 filing?

The filing covers a potential sale of 22,500 shares of CSTL common stock. These shares are planned for sale through a broker-dealer and reflect stock received from prior equity compensation grants.

What is the aggregate market value of CSTL shares in the planned Form 144 sale?

The planned sale has an indicated aggregate market value of $630,000. This value corresponds to the 22,500 shares of CSTL common stock referenced in the Form 144 notice.

When is the CSTL Form 144 sale expected to occur?

The Form 144 indicates sales may occur on or after July 31, 2026. This is the date associated with the proposed disposition of 22,500 CSTL shares through a broker-dealer.

What type of compensation awards generated the CSTL shares in this Form 144?

The shares arise from Restricted Stock Units and Restricted Stock Awards. These equity awards were acquired as compensation on several dates, including 12/10/2021, 02/28/2022, 08/09/2024, 12/09/2024, and 12/10/2024.

How many CSTL shares were in the largest individual compensation grant referenced?

The largest single compensation grant listed is 12,074 shares of CSTL common stock. This grant was acquired as compensation in the form of Restricted Stock Units dated 12/09/2024.

Does the CSTL Form 144 list any securities sold in the past three months?

The section for Securities Sold During The Past 3 Months appears without populated sale entries. The filing instead details the planned sale of 22,500 shares and the underlying compensation grants.

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

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Available on EDGAR 07/31/2026 - 04:53 PM Accepted by SEC EDGAR 07/31/2026 - 04:52 PM 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	0001856542
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	1-866-788-9007
Name of Person for Whose Account the Securities are To Be Sold	Tobin Juvenal
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	Chief Commercial 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	Goldman Sachs & Co. LLC 200 West Street New York NY 10282	22500	630000	30329952	07/31/2026	NASD

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	12/10/2024	Acquired as compensation -- Restricted Stock Units	Issuer			4666	12/10/2024	Compensation
Common	12/10/2021	Acquired as compensation -- Restricted Stock Units	Issuer			1323	12/10/2021	Compensation
Common	02/28/2022	Acquired as compensation -- Restricted Stock Awards	Issuer			494	02/28/2022	Compensation
Common	12/09/2024	Acquired as compensation -- Restricted Stock Units	Issuer			12074	12/09/2024	Compensation
Common	08/09/2024	Acquired as compensation -- Restricted Stock Units	Issuer			2620	08/09/2024	Compensation
Common	12/10/2024	Acquired as compensation -- Restricted Stock Units	Issuer			1323	12/10/2024	Compensation

* 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	The sales of shares set forth herein are made in connection with a selling plan dated 12/10/2025 that is intended to comply with Rule 10b5-1(c).
Date of Notice	07/31/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	12/10/2025
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	Goldman Sachs & Co. LLC on behalf of Tobin Juvenal
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)