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

Rhea-AI Filing Summary

Gossamer Bio, Inc. (GOSS) – Form 4 insider transaction

Director Thomas O. Daniel received an equity award on 06/25/2025 consisting of 115,000 non-qualified stock options with an exercise price of $1.36 and an expiration date of 06/24/2035. The grant was made under the company’s Non-Employee Director Compensation Program.

All options vest in full on the earlier of (a) the first anniversary of the grant date or (b) the next annual meeting of shareholders, contingent on continued board service. The filing lists the transaction code “A” (acquisition) and shows 115,000 derivative securities beneficially owned directly after the transaction. No common shares were bought or sold.

• Standard director compensation; no immediate cash outlay by the insider.
• Filing signed on 06/26/2025 by Attorney-in-Fact Jeff Boerneke.
• No other changes in ownership disclosed.

Insights

Corporate Governance Analyst

TL;DR: Routine option grant aligns director incentives; limited dilution, neutral impact.

The award size (115,000 options) and 10-year term are typical for small-cap biotech boards. A one-year vesting schedule encourages near-term engagement while preserving flexibility should the director depart. At today’s strike of $1.36, upside participation begins only after meaningful share appreciation, providing shareholders with first-loss protection. Because no shares were sold, the filing does not signal insider sentiment; it is purely compensatory. Potential dilution—roughly 0.1-0.2 % of outstanding shares based on 90-100 million shares—is immaterial. Overall, this is routine governance housekeeping and should not influence valuation or risk models.

Portfolio Manager

TL;DR: Neutral—standard director pay; no buy/sell signal detected.

For investors, the key takeaway is that no insider purchased or disposed of common stock. While option grants can indicate confidence, this issuance is automatic under the board’s compensation plan and therefore carries little informational value. The strike price of $1.36 merely mirrors recent market levels, so there is no embedded discount. I view the filing as non-impactful to the investment thesis and would not adjust position sizing or valuation models based on this disclosure.

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
Estimated average burden
hours per response:			0.5

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^*

Daniel Thomas O

(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

Who received the stock option grant disclosed in GOSS's Form 4?

Director Thomas O. Daniel was the reporting person receiving the options.

How many options were granted to the GOSS director?

A total of 115,000 non-qualified stock options were granted.

What is the exercise price of the newly issued GOSS options?

The options carry an exercise (strike) price of $1.36 per share.

When do the options granted to the GOSS director vest?

They vest fully on the earlier of one year from grant or the next annual shareholder meeting, subject to continued board service.

Does the filing indicate any purchase or sale of GOSS common stock?

No. The Form 4 only reports an option acquisition; no common shares were bought or sold.