Form 4 Filing for Gossamer Bio, Inc.

This filing details significant transactions by Hasnain Faheem, President & CEO of Gossamer Bio, Inc. On August 24, 2026, Mr. Faheem acquired 166 pre-funded warrants for Series A-1 Preferred Stock at $999.999 each, which are convertible into common stock under specific conditions related to stockholder approval and beneficial ownership limitations. Additionally, he was granted stock options to purchase 5,800,051 shares of common stock at an exercise price of $0.175. The vesting of these options is contingent upon FDA approval of seralutinib, with a phased vesting schedule over 24 months post-approval, or a pro-rata vesting over 24 months if approval is delayed beyond two years from the grant date. These transactions indicate a substantial increase in Mr. Faheem's potential equity stake in the company.