[Form 4] Gossamer Bio, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Gossamer Bio director Steven D. Nathan received a stock option grant on June 25, 2025, as reported in this Form 4 filing. The derivative securities transaction details include:

• Grant of 115,000 stock options to purchase common stock
• Exercise price set at $1.36 per share
• Options expire on June 24, 2035
• Vesting occurs at the earlier of:
  • First anniversary of grant date
  • Next annual stockholder meeting

The award was made under the company's Non-Employee Director Compensation Program. Vesting is contingent on Nathan's continued service on the board of directors through the vesting date. The filing was submitted by attorney-in-fact Jeff Boerneke on June 26, 2025.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Nathan Steven D

(Last) (First) (Middle)

3115 MERRYFIELD ROW, SUITE 120

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Gossamer Bio, Inc. [ GOSS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
06/25/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$1.36	06/25/2025		A		115,000(1)		(2)	06/24/2035	Common Stock	115,000	$0	115,000	D

Explanation of Responses:

1. Award made pursuant to Non-Employee Director Compensation Program.

2. The entire number of shares subject to this option becomes fully vested and exercisable on the first to occur of (a) the first anniversary of the grant date or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the board of directors of the Issuer through such vesting date.

Remarks:

	/s/ Jeff Boerneke, Attorney-in-Fact	06/26/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What stock options did GOSS director Steven Nathan receive on June 25, 2025?

Steven Nathan received 115,000 stock options with an exercise price of $1.36 per share. These options were granted under the Non-Employee Director Compensation Program and will expire on June 24, 2035.

When do Steven Nathan's GOSS stock options vest?

The stock options will fully vest on the earlier of: (a) the first anniversary of the grant date (June 25, 2026) or (b) GOSS's next annual stockholder meeting, provided Nathan continues serving on the board of directors through the vesting date.

What is the exercise price of GOSS director Steven Nathan's new stock options?

The stock options were granted with an exercise price of $1.36 per share.

How long does Steven Nathan have to exercise his GOSS stock options?

The stock options have a 10-year term and will expire on June 24, 2035.

What is Steven Nathan's role at GOSS according to the Form 4?

According to the Form 4, Steven Nathan serves as a Director of Gossamer Bio, Inc. (GOSS). His address is listed as 3115 Merryfield Row, Suite 120, San Diego, CA 92121.