Robert Doebele - 23 Jan 2026 Form 4 Insider Report for Boundless Bio, Inc. (BOLD)

Reporting relationship: Chief Medical Officer
Issuer ticker: BOLD
Reported as of: 23 Jan 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 26 Jan 2026, 07:00:06 UTC
Prior SEC filing: 03 Feb 2025
Source filing: View source filing
Reporting owner signature: /s/ Jessica Oien, Attorney-in- Fact for Robert Doebele

Key filing fact

Robert Doebele filed Form 4 for Boundless Bio, Inc. (BOLD) on 26 Jan 2026.

Key facts

This page summarizes Robert Doebele's Form 4 filing for Boundless Bio, Inc. (BOLD).
1 reported transaction and 1 derivative row are listed below.
Accepted by SEC: 26 Jan 2026, 07:00.

Change

Previous filing in this sequence was filed on 03 Feb 2025.
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 0001856681 Primary reporting owner

Doebele Robert

Relationship: Chief Medical Officer
Address: C/O BOUNDLESS BIO, INC., 10955 ALEXANDRIA WAY, SUITE 100, SAN DIEGO
Signature: /s/ Jessica Oien, Attorney-in- Fact for Robert Doebele
Signature date: 23 Jan 2026

Reported derivative securities

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

BOLD transaction Derivative

Stock Option (right to buy)

Award

Transaction value: $0
Shares: +230,000
Change %
Price: $0.000000
Shares after: 230,000
Date: 23 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 230,000
Exercise price: $1.26
Footnotes: F1

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

The vesting commencement date is January 1, 2026. The stock option vests in 48 substantially equal monthly installments. Accordingly, 1/48th of this stock option vests on February 1, 2026, and monthly thereafter.