Castle Biosciences officer proposes $148K share sale

The proposed shares are associated with a cash exercise of stock options with the issuer.

Rhea-AI Filing Summary

Castle Biosciences Inc. (CSTL) lists a proposed sale by officer Kristen Oelschlager of 4,153 common shares, with Morgan Stanley Smith Barney LLC named as broker and October 1, 2026 as the approximate sale date. The related securities information gives an aggregate market value of $147,556.09 and describes the shares as tied to a cash exercise of stock options with the issuer.

Key Figures

Proposed sale: 4,153 common shares Aggregate market value: $147,556.09 Issuer shares outstanding: 30,549,507 shares +4 more

7 metrics

Proposed sale 4,153 common shares Approximate sale date: October 1, 2026

Aggregate market value $147,556.09 Proposed sale

Issuer shares outstanding 30,549,507 shares Reported in the securities information

Prior sale by Kristen Oelschlager 4,152 shares September 1, 2026

Prior sale by The Fritz Shorter Trust 12,384 shares August 25, 2026

Prior sale by The Fritz Shorter Trust 12,218 shares August 24, 2026

Prior sale by Kristen Oelschlager 8,586 shares August 3, 2026

Key Terms

Rule 144, 10b5-1 Sales, Exercise of Stock Options

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

10b5-1 Sales regulatory

"10b5-1 Sales for KRISTEN OELSCHLAGER"

10b5-1 sales are pre-arranged stock-trading plans that let company insiders automatically buy or sell shares according to a fixed schedule or formula, even if they later learn confidential information. Think of it as setting up an automatic thermostat for trades: it creates a clear, documented path that can protect insiders from insider-trading accusations and gives investors a signal about predictable insider activity—though it can also simply be a way for insiders to diversify or raise cash.

Exercise of Stock Options financial

"Exercise of Stock Options"

FAQ

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

How many CSTL shares does Kristen Oelschlager plan to sell?

Kristen Oelschlager's notice lists 4,153 common shares for sale, with an aggregate market value of $147,556.09. Morgan Stanley Smith Barney LLC is named as broker, and October 1, 2026 is the approximate sale date.

What recent CSTL share sales are listed for Kristen Oelschlager?

The prior-three-months section lists Kristen Oelschlager's 4,152-share sale on September 1, 2026 and 8,586-share sale on August 3, 2026 as 10b5-1 sales. It also lists The Fritz Shorter Trust's 12,384-share and 12,218-share sales on August 25 and August 24, 2026, respectively.

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

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Available on EDGAR 10/01/2026 - 04:24 PM Accepted by SEC EDGAR 10/01/2026 - 04:24 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	0001856565
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	8667889007
Name of Person for Whose Account the Securities are To Be Sold	KRISTEN OELSCHLAGER
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	4153	147556.09	30549507	10/01/2026	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	10/01/2026	Exercise of Stock Options	Issuer			4153	10/01/2026	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

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
10b5-1 Sales for KRISTEN OELSCHLAGER 1500 W. Parkwood Ave, Suite 400 Friendswood TX 77546	Common	09/01/2026	4152	138643.58
The Fritz Shorter Trust 1500 W. Parkwood Ave, Suite 400 Friendswood TX 77546	Common	08/25/2026	12384	426276.84
The Fritz Shorter Trust 1500 W. Parkwood Ave, Suite 400 Friendswood TX 77546	Common	08/24/2026	12218	411587.77
10b5-1 Sales for KRISTEN OELSCHLAGER 1500 W. Parkwood Ave, Suite 400 Friendswood TX 77546	Common	08/03/2026	8586	255633.70

144: Remarks and Signature

Remarks
Date of Notice	10/01/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	03/17/2026
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/ Kristen Oelschlager
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)