Kevin Tang, a director and 10% owner of Boundless Bio, Inc. (NASDAQ:BOLD), filed a Form 4 on October 26, 2026, disclosing three open-market purchases of common stock totaling 21,640 shares between October 22 and October 26, 2026.

Key Highlights

  • Three purchases in three days: Tang acquired 5,800 shares on October 22, 6,234 shares on October 23, and 9,606 shares on October 26, 2026.
  • Weighted-average prices: The October 22 purchase carried a weighted-average price of $2.40 per share; the October 23 and October 26 purchases each carried a weighted-average price of $2.38 per share.
  • Post-transaction ownership: Following the final transaction, Tang's indirect beneficial ownership stood at 3,011,749 shares of common stock.
  • Indirect ownership structure: All shares are held indirectly through Tang Capital Partners, LP; Tang Capital Partners International, LP; Tang Capital Partners III, Inc.; and Tang Capital Partners IV, Inc.
  • Dual reporting persons: The filing was signed by both Kevin Tang individually and Kevin Tang as Manager of Tang Capital Management LLC, the general partner of the relevant funds.

Tang Capital Entities Accumulate Additional Boundless Bio Common Stock

According to the filing, all three transactions were coded "P," indicating open-market purchases. The shares acquired were added to an existing indirect position. On October 22, 2026, 5,800 shares were purchased at a weighted-average price of $2.40, with individual transaction prices ranging from $2.39 to $2.40. On October 23, 2026, 6,234 shares were purchased at a weighted-average price of $2.38, with prices ranging from $2.36 to $2.40. On October 26, 2026, 9,606 shares were purchased at a weighted-average price of $2.38, with prices ranging from $2.37 to $2.40.

The filing discloses the indirect ownership breakdown across four entities: Tang Capital Partners, LP holds 691,177 shares; Tang Capital Partners International, LP holds 950,804 shares; Tang Capital Partners III, Inc. holds 691,170 shares; and Tang Capital Partners IV, Inc. holds 678,598 shares. According to the filing, Kevin Tang is the sole manager of Tang Capital Management, LLC, which serves as the general partner of Tang Capital Partners, LP and Tang Capital Partners International, LP. Tang Capital Partners III, Inc. and Tang Capital Partners IV, Inc. are described as indirectly wholly owned by Tang Capital Partners, LP. The filing notes that Mr. Tang "has a pecuniary interest in the shares beneficially held by TCP, TCPI, TCP III and TCP IV."

The reporting persons stated they will provide the issuer, any security holder, or the SEC staff, upon request, all information regarding the number of shares purchased at each specific price within the disclosed ranges.

What Was Disclosed

Kevin Tang and Tang Capital Management LLC jointly reported three purchases of Boundless Bio common stock between October 22 and October 26, 2026, totaling 21,640 shares at weighted-average prices between $2.38 and $2.40, bringing indirect beneficial ownership to 3,011,749 shares.