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Castle Biosciences (CSTL) COO sells 8,586 shares in 10b5-1 plan

Filing Impact
(Moderate)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Castle Biosciences chief operating officer Kristen M. Oelschlager reported selling a total of 8,586 shares of common stock on August 3, 2026, in three open-market transactions at weighted-average prices of $29.12, $30.00 and $30.62 per share, each executed across multiple trades within disclosed price ranges. These sales were made pursuant to a Rule 10b5-1 trading plan adopted on March 17, 2026, indicating they were pre-scheduled. Oelschlager also has indirect ownership of 97,251 shares held by The Fritz Shorter Trust, where she and her spouse serve as trustees and beneficiaries.

Positive

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Negative

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Insider Oelschlager Kristen M
Role Chief Operating Officer
Sold 8,586 shs ($256K)
Type Security Shares Price Value
Sale Common Stock F1, F2 3,000 $29.12 $87K
Sale Common Stock F1, F3 4,486 $30.00 $135K
Sale Common Stock F1, F4 1,100 $30.62 $34K
holding Common Stock F5 -- -- --
Holdings After Transaction: Common Stock — 13,288 shares (Direct); Common Stock — 97,251 shares (Indirect, The Fritz Shorter Trust)
Footnotes (5)
  1. F1. These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person, on March 17, 2026.
  2. F2. This transaction was executed in multiple trades at prices ranging from $28.46 to $29.45, 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.
  3. F3. This transaction was executed in multiple trades at prices ranging from $29.53 to $30.44, 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.
  4. F4. This transaction was executed in multiple trades at prices ranging from $30.55 to $30.71, 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.
  5. F5. Held by the Fritz Shorter Trust of which the Reporting Person and her spouse are the trustees and beneficiaries.
Shares sold 8,586 shares Total common shares sold by COO Kristen M. Oelschlager on August 3, 2026
Sale price block 1 $29.12 per share Weighted-average price for 3,000 shares; trades ranged from $28.46 to $29.45
Sale price block 2 $30.00 per share Weighted-average price for 4,486 shares; trades ranged from $29.53 to $30.44
Sale price block 3 $30.62 per share Weighted-average price for 1,100 shares; trades ranged from $30.55 to $30.71
Indirect holdings 97,251 shares Common shares held indirectly through The Fritz Shorter Trust as of August 3, 2026
Rule 10b5-1 plan regulatory
"These transactions were made pursuant to a Rule 10b5-1 plan"
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
weighted-average sale price financial
"The price reported above reflects the weighted-average sale price"
open market or private transaction financial
"Sale in open market or private transaction"
The Fritz Shorter Trust financial
"Held by the Fritz Shorter Trust of which the Reporting Person"

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

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FAQ

What insider transaction did Castle Biosciences (CSTL) report for Kristen M. Oelschlager?
Kristen M. Oelschlager, COO of Castle Biosciences, reported selling 8,586 shares of common stock. The sales occurred on August 3, 2026 in three open-market transactions executed under a pre-established Rule 10b5-1 trading plan, with prices disclosed as weighted-average sale prices.

At what prices were the CSTL shares sold by COO Kristen Oelschlager?
The reported weighted-average sale prices were $29.12, $30.00 and $30.62 per share. Each block was executed in multiple trades within ranges from $28.46–$30.71, and the company notes that full trade-by-trade price details are available upon request.

Were Kristen Oelschlager’s CSTL share sales made under a Rule 10b5-1 trading plan?
Yes. The transactions are described as made pursuant to a Rule 10b5-1 plan. A footnote states the plan was adopted by Kristen M. Oelschlager on March 17, 2026, indicating the sales were pre-arranged rather than discretionary trades based on near-term market developments.

How many Castle Biosciences (CSTL) shares does Kristen Oelschlager still hold indirectly?
After the reported transactions, Kristen M. Oelschlager is shown with 97,251 shares held indirectly. These shares are owned through The Fritz Shorter Trust, which is described as a trust where she and her spouse act as both trustees and beneficiaries.

What is The Fritz Shorter Trust’s role in CSTL insider ownership for Kristen Oelschlager?
The Fritz Shorter Trust holds 97,251 Castle Biosciences shares attributed to Kristen Oelschlager as indirect ownership. A footnote explains that she and her spouse are the trust’s trustees and beneficiaries, linking this trust-held position to her overall economic interest in the company.
SEC Form 4
FORM 4UNITED 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).
X
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.
1500 W. PARKWOOD AVE SUITE 400
(Street)
FRIENDSWOOD TEXAS 77546
(City)(State)(Zip)
UNITED STATES
(Country)		2. Issuer Name and Ticker or Trading Symbol
CASTLE BIOSCIENCES INC [ CSTL ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Operating Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
08/03/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
CodeVAmount(A) or (D)Price
Common Stock08/03/2026S(1)3,000D$29.12(2)18,874D
Common Stock08/03/2026S(1)4,486D$30(3)14,388D
Common Stock08/03/2026S(1)1,100D$30.62(4)13,288D
Common Stock97,251IThe Fritz Shorter Trust(5)
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person, on March 17, 2026.
2. This transaction was executed in multiple trades at prices ranging from $28.46 to $29.45, 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.
3. This transaction was executed in multiple trades at prices ranging from $29.53 to $30.44, 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.
4. This transaction was executed in multiple trades at prices ranging from $30.55 to $30.71, 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.
5. Held by the Fritz Shorter Trust of which the Reporting Person and her spouse are the trustees and beneficiaries.
Remarks:
/s/ Frank Stokes, Attorney-in-fact08/05/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR