Kristen M. Oelschlager - 03 Mar 2026 Form 4 Insider Report for CASTLE BIOSCIENCES INC (CSTL)

Reporting relationship: Chief Operating Officer
Issuer ticker: CSTL
Reported as of: 03 Mar 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 05 Mar 2026, 17:16:56 UTC
Prior SEC filing: 14 Jan 2026
Next SEC filing: 18 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Frank Stokes, Attorney-in-fact

Key filing fact

Kristen M. Oelschlager filed Form 4 for CASTLE BIOSCIENCES INC (CSTL) on 05 Mar 2026.

Key facts

This page summarizes Kristen M. Oelschlager's Form 4 filing for CASTLE BIOSCIENCES INC (CSTL).
6 reported transactions and 3 derivative rows are listed below.
Accepted by SEC: 05 Mar 2026, 17:16.

Change

Previous filing in this sequence was filed on 14 Jan 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001856565 Primary reporting owner

Oelschlager Kristen M

Relationship: Chief Operating Officer
Address: C/O CASTLE BIOSCIENCES, INC., 1500 W. PARKWOOD AVE SUITE 400, FRIENDSWOOD
Signature: /s/ Frank Stokes, Attorney-in-fact
Signature date: 05 Mar 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CSTL transaction

Common Stock

Tax liability

Transaction value
Shares: -2,427
Change %: -11%
Price: $27.57^*
Shares after: 20,068
Date: 03 Mar 2026
Ownership: Direct
Footnotes: F1, F2

CSTL transaction

Common Stock

Options Exercise

Transaction value
Shares: +25,771
Change %: +128%
Price
Shares after: 45,839
Date: 04 Mar 2026
Ownership: Direct
Footnotes: F3

CSTL transaction

Common Stock

Tax liability

Transaction value
Shares: -6,792
Change %: -15%
Price: $28.17^*
Shares after: 39,047
Date: 04 Mar 2026
Ownership: Direct

CSTL holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 97,251
Date: 03 Mar 2026
Ownership: The Fritz Shorter Trust
Footnotes: F4

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CSTL transaction Derivative

Restricted Stock Units

Award

Transaction value
Shares: +48,367
Change %
Price: $0.000000^*
Shares after: 48,367
Date: 03 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 48,367
Exercise price
Footnotes: F3, F5

CSTL transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -13,811
Change %: -33%
Price: $0.000000^*
Shares after: 27,621
Date: 04 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 13,811
Exercise price
Footnotes: F3, F6

CSTL transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -11,960
Change %: -25%
Price: $0.000000^*
Shares after: 35,878
Date: 04 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 11,960
Exercise price
Footnotes: F3, F7

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 7 footnotes

Footnote F1

Reflects the withholding of shares of the Issuer's common stock to satisfy tax withholding obligations in connection with the delivery of vested performance stock units reported on January 12, 2026.

Footnote F2

Includes 965 shares acquired on February 27, 2026, under the Issuer's employee stock purchase plan.

Footnote F3

Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.

Footnote F4

Held by the Fritz Shorter Trust of which the Reporting Person and her spouse are the trustees and beneficiaries.

Footnote F5

The RSU's vest in four equal annual installments beginning on March 03, 2027.

Footnote F6

On March 4, 2024, the Reporting Person was granted 55,243 RSUs which vest in four equal installments beginning on March 4, 2025.

Footnote F7

On March 4, 2025, the Reporting Person was granted 47,838 RSUs which vest in four equal installments beginning on March 4, 2026.