Gossamer Bio, Inc. — Director's Dealing 2025

Oct 2, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Gossamer Bio, Inc. (GOSS)
CIK: 0001728117
Period of Report: 2025-10-01

Reporting Person: Peterson Caryn (EVP, Regulatory Affairs)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-10-01	Common Stock	A	125000	—	Acquired	174833	Direct

Footnotes

F1: Represents performance stock unit award, which will vest in full upon the earlier of (i) the approval of a new drug application for seralutinib or (ii) a change in control, in either case on or prior to the fourth anniversary of the grant date, and subject to the Reporting Person's continuous service to the Issuer.