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

Rhea-AI Filing Summary

Gossamer Bio, Inc. (GOSS) filed a Form 4 disclosing that non-employee director John D. Quisel received a new stock-option award on 06/25/2025. The grant covers 115,000 options to purchase GOSS common shares at an exercise price of $1.36 per share. These options carry a ten-year term, expiring on 06/24/2035.

According to the issuer’s Non-Employee Director Compensation Program, the entire award vests on the earlier of (a) the first anniversary of the grant date or (b) the next annual meeting of shareholders, provided the director remains on the board through the vesting date. No shares or options were sold or disposed of, and Quisel’s total beneficial holding of derivative securities increased to 115,000 options following the transaction. The filing indicates routine equity-based compensation and does not reference any 10b5-1 trading plan.

Insights

Financial Analyst

TL;DR: Routine director option grant; neutral impact, minimal dilution.

The Form 4 details a standard non-employee director compensation award: 115,000 stock options at a strike roughly in line with prevailing market prices. With no immediate share issuance and vesting deferred for up to one year, the transaction adds only potential dilution and signals continued board engagement. Because the award size is immaterial relative to Gossamer’s outstanding shares and does not involve open-market purchases or sales, the filing is best viewed as administrative. Investors should monitor future exercise or sale activity, but today’s disclosure has no direct impact on cash flow, earnings, or governance risk.

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^*

Quisel John 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 security was reported in GOSS's latest Form 4?

Stock options granting the right to buy common shares of Gossamer Bio.

How many GOSS stock options did Director John D. Quisel receive?

He received 115,000 options.

What is the exercise price and expiration date of the new options?

The strike price is $1.36; the options expire on 06/24/2035.

When will the options granted to John D. Quisel vest?

They fully vest on the earlier of the first anniversary of 06/25/2025 or the next annual shareholder meeting.

Did the Form 4 disclose any sale of GOSS shares?

No. The filing shows only an acquisition of derivative securities; no dispositions were reported.