X0202 SCHEDULE 13G/A 0001404574-26-000006 0001404574 XXXXXXXX LIVE 1 Common Stock, $0.0001 par value per share 03/18/2026 0001728117 Gossamer Bio, Inc. 38341P102 3115 MERRYFIELD ROW SUITE 120 SAN DIEGO CA 92121 Rule 13d-1(c) 683 Capital Management, LLC DE 0.00 9331304.00 0.00 9331304.00 9331304.00 N 3.9 IA 683 Capital Partners, LP DE 0.00 9331304.00 0.00 9331304.00 9331304.00 N 3.9 PN Ari Zweiman X1 0.00 9331304.00 0.00 9331304.00 9331304.00 N 3.9 IN Gossamer Bio, Inc. 3115 MERRYFIELD ROW, SUITE 120, SAN DIEGO, CALIFORNIA 92121 683 Capital Management, LLC 683 Capital Partners, LP Ari Zweiman The principal business address for each of the Reporting Persons is 1700 Broadway, Suite 4200, New York, New York 10019. 683 Capital Management, LLC - DELAWARE 683 Capital Partners, LP - DELAWARE Ari Zweiman - UNITED STATES Y As of March 24, 2026, 683 Capital Partners, LP beneficially owned 5,000,000 shares of Common Stock and warrants to purchase 4,331,304 shares of Common Stock which are currently exercisable. 683 Capital Management, LLC, as the investment manager of 683 Capital Partners, LP, may be deemed to have beneficially owned the 5,000,000 shares of Common Stock and warrants to purchase 4,331,304 shares of Common Stock beneficially owned by 683 Capital Partners, LP. Ari Zweiman, as the Managing Member of 683 Capital Management, LLC, may be deemed to have beneficially owned the 5,000,000 shares of Common Stock and warrants to purchase 4,331,304 shares of Common Stock beneficially owned by 683 Capital Management, LLC. The following percentage is based on 234,696,281 shares of common stock ($0.0001 par value) outstanding as of March 10, 2026, as disclosed in the Issuer's Form 10-K filed on March 17, 2026, plus 4,331,304 shares of Common Stock issuable upon exercise of currently exercisable warrants held by the Reporting Persons. As of March 24, 2026, the Reporting Persons may be deemed to have beneficially owned approximately 3.90% of the outstanding Common Shares. 3.90 See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. N Y Y Y N See Exhibit A to Schedule 13G filed on March 2, 2026. Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. 683 Capital Management, LLC Ari Zweiman 03/24/2026 683 Capital Partners, LP Ari Zweiman 03/24/2026 Ari Zweiman Ari Zweiman 03/24/2026