SEC Form 4 · accession 0001178579-26-000009

Boundless Bio, Inc. · BOLD

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owners

10% Owner

10% Owner

Period of report

Jun 30, 2026

Accepted (ET)

Jul 2, 2026 · 7:45 pm EDT

Rule 10b5-1 plan

box not checked

Issuer CIK

0001782303

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F2	Jun 30, 2026	P	25,930	$2.54	A	2,559,775	I	By LP
Common Stock^F3,F2	Jun 30, 2026	P	100	$2.50	A	2,559,875	I	By LP
Common Stock^F4,F2	Jul 1, 2026	P	71,612	$2.49	A	2,631,487	I	By LP
Common Stock^F5,F2	Jul 2, 2026	P	9,821	$2.49	A	2,641,308	I	By LP

No Table II lines on this filing.

F1The prices reported are weighted-average prices. These shares were purchased in multiple transactions at prices ranging from $2.49 to $2.60. 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 purchased at each price within the ranges set forth in Footnotes 1 and 3 through 5.
F2Tang Capital Partners, LP ("TCP") beneficially owns 605,296 shares, Tang Capital Partners International, LP ("TCPI") beneficially owns 825,422 shares, Tang Capital Partners III, Inc. ("TCP III") beneficially owns 605,294 shares, and Tang Capital Partners IV, Inc. ("TCP IV") beneficially owns 605,296 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.
F3These shares were all purchased at $2.50.
F4These shares were purchased in multiple transactions at prices ranging from $2.46 to $2.50.
F5These shares were purchased in multiple transactions at prices ranging from $2.47 to $2.50.