Form 3 Filing for Boundless Bio, Inc. - Initial Statement of Beneficial Ownership

This filing reports the initial beneficial ownership of Boundless Bio, Inc. (BOLD) by Kevin Tang and Tang Capital Management LLC, as of June 25, 2026. Kevin Tang is identified as a 10% owner. The shares are beneficially owned through various entities including Tang Capital Partners, LP, Tang Capital Partners International, LP, Tang Capital Partners III, Inc., and Tang Capital Partners IV, Inc. Kevin Tang, through his management role in Tang Capital Management, LLC, has a pecuniary interest in these shares. Following these transactions, a total of 2,247,512 shares of Common Stock are beneficially owned, with ownership indicated as indirect.