Waage Christian - Mar 20, 2023 Form 4 Insider Report for Gossamer Bio, Inc. (GOSS)

Role: EVP, Tech Ops and Admin
Signature: /s/ Jeff Boerneke, Attorney-in-Fact
Stock symbol: GOSS
Transactions as of: Mar 20, 2023
Transactions value $: $22,145
Form type: 4
Date filed: 3/22/2023, 05:19 PM
Previous filing: Dec 20, 2022
Next filing: May 9, 2023

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	GOSS	Common Stock	Purchase	$22.1K	+18.5K	+133.21%	$1.20	32.4K	Mar 20, 2023	By family trust
holding	GOSS	Common Stock						582K	Mar 20, 2023	Direct
holding	GOSS	Common Stock						22.2K	Mar 20, 2023	By trust FBO son

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	GOSS	Stock Option (Right to Buy)	Award	$0	+158K		$0.00	158K	Mar 20, 2023	Common Stock	158K	$1.21	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	25% of the total number of shares subject to the option will vest on March 20, 2024 and 1/48th of the total number of shares subject to the option vest on the last day of each one-month period thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.