Kevin Tang - 26 Aug 2026 Form 4 Insider Report for Boundless Bio, Inc. (BOLD)

Reporting relationship: 10%+ Owner
Issuer ticker: BOLD
Reported as of: 26 Aug 2026
Net transaction value: -$54,351
SEC form: 4
Accepted by SEC: 28 Aug 2026, 16:16:09 UTC
Prior SEC filing: 21 Jul 2026
Source filing: View source filing
Reporting owner signature: Kevin Tang

Key filing fact

Kevin Tang filed Form 4 for Boundless Bio, Inc. (BOLD) on 28 Aug 2026.

Key facts

This page summarizes Kevin Tang's Form 4 filing for Boundless Bio, Inc. (BOLD).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 28 Aug 2026, 16:16.

Change

Previous filing in this sequence was filed on 21 Jul 2026.
Current net transaction value: -$54,351.

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 (2)

CIK 0001178579 Primary reporting owner

TANG KEVIN

Relationship: 10%+ Owner
Address: 4747 EXECUTIVE DRIVE, SUITE 210, SAN DIEGO
Signature: Kevin Tang
Signature date: 28 Aug 2026

CIK 0001232621

TANG CAPITAL MANAGEMENT LLC

Relationship: 10%+ Owner
Address: 4747 EXECUTIVE DRIVE, SUITE 210, SAN DIEGO
Signature: Kevin Tang, Manager
Signature date: 28 Aug 2026

Reported non-derivative transactions

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

BOLD transaction

Common Stock

Sale

Transaction value: $54,351
Shares: -18,300
Change %: -0.64%
Price: $2.97
Shares after: 2,840,635
Date: 26 Aug 2026
Ownership: See Footnote
Footnotes: F1, F2, F3

BOLD transaction

Common Stock

Sale

Transaction value: $54,351
Shares: -18,300
Change %: -0.64%
Price: $2.97
Shares after: 2,840,635
Date: 26 Aug 2026
Ownership: See Footnote
Footnotes: F1, F2, F3

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

The Reporting Persons have delivered to the Issuer the full amount of the disgorgeable profit arising the sale reported herein, in the amount of $10,046.70.

Footnote F2

The price reported herein is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $2.90 to $3.03. The Reporting Persons undertake to provide the Issuer, any security holder of the Issuer or the SEC staff, upon request, all information regarding the number of shares sold at each price within the range set forth in Footnote 2.

Footnote F3

Tang Capital Partners, LP ("TCP") beneficially owns 655,170 shares, Tang Capital Partners International, LP ("TCPI") beneficially owns 887,715 shares, Tang Capital Partners III, Inc. ("TCP III") beneficially owns 655,161 shares, and Tang Capital Partners IV, Inc. ("TCP IV") beneficially owns 642,589 shares. Kevin Tang is the sole manager of Tang Capital Management, LLC, which is the general partner of TCP and TCPI. Kevin Tang is the sole director and Chief Executive Officer of TCP III and TCP IV, which are indirectly wholly owned by TCP. Mr. Tang has a pecuniary interest in the shares beneficially held by TCP, TCPI, TCP III and TCP IV.