Tobin W. Juvenal - 31 Jul 2026 Form 4 Insider Report for CASTLE BIOSCIENCES INC (CSTL)

Reporting relationship: Chief Commercial Officer
Issuer ticker: CSTL
Reported as of: 31 Jul 2026
Net transaction value: -$556,175
SEC form: 4
Accepted by SEC: 04 Aug 2026, 16:36:12 UTC
Prior SEC filing: 26 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Frank Stokes, Attorney-in-fact

Key filing fact

Tobin W. Juvenal filed Form 4 for CASTLE BIOSCIENCES INC (CSTL) on 04 Aug 2026.

Key facts

This page summarizes Tobin W. Juvenal's Form 4 filing for CASTLE BIOSCIENCES INC (CSTL).
4 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 04 Aug 2026, 16:36.

Change

Previous filing in this sequence was filed on 26 May 2026.
Current net transaction value: -$556,175.

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 0001856542 Primary reporting owner

Juvenal Tobin W

Relationship: Chief Commercial Officer
Address: C/O CASTLE BIOSCIENCES, INC., 1500 W. PARKWOOD AVE SUITE 400, FRIENDSWOOD
Signature: /s/ Frank Stokes, Attorney-in-fact
Signature date: 04 Aug 2026

Reported non-derivative transactions

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

CSTL transaction

Common Stock

Sale

Transaction value: $235,033
Shares: -8,149
Change %: -8.3%
Price: $28.84
Shares after: 89,886
Date: 31 Jul 2026
Ownership: Direct
Footnotes: F1, F2

CSTL transaction

Common Stock

Sale

Transaction value: $215,039
Shares: -7,270
Change %: -8.1%
Price: $29.58
Shares after: 82,616
Date: 31 Jul 2026
Ownership: Direct
Footnotes: F1, F3

CSTL transaction

Common Stock

Sale

Transaction value: $57,229
Shares: -1,891
Change %: -2.3%
Price: $30.26
Shares after: 80,725
Date: 31 Jul 2026
Ownership: Direct
Footnotes: F1, F4

CSTL transaction

Common Stock

Sale

Transaction value: $48,872
Shares: -1,730
Change %: -2.1%
Price: $28.25
Shares after: 78,995
Date: 03 Aug 2026
Ownership: Direct
Footnotes: F1, F5

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

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 5 footnotes

Footnote F1

This transaction was made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on December 10, 2025.

Footnote F2

This transaction was executed in multiple trades at prices ranging from $28.150 to $29.140, 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.

Footnote F3

This transaction was executed in multiple trades at prices ranging from $29.150 to $30.130, 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.

Footnote F4

This transaction was executed in multiple trades at prices ranging from $30.150 to $30.645, 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.

Footnote F5

This transaction was executed in multiple trades at prices ranging from $28.030 to $28.630, 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.