Gossamer Bio (GOSS) reprices multiple stock option grants for COO/CFO

Rhea-AI Filing Summary

Gossamer Bio, Inc. reported that COO/CFO Bryan Giraudo had several existing stock option awards canceled and reissued as part of a one-time option repricing under the company’s 2019 Incentive Award Plan.

The repricing, effective March 19, 2026, reduced the exercise price of these options to $0.45 per share from prior exercise prices ranging from $0.838 to $2.88, while keeping all other terms, including vesting schedules and option terms, unchanged. These are compensation-related derivative transactions and do not involve open-market purchases or sales of common stock.

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

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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^*

Giraudo Bryan

(Last) (First) (Middle)

3115 MERRYFIELD ROW, SUITE 120

(Street)

SAN DIEGO CALIFORNIA 92121

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/19/2026

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

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

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

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)	$2.88	03/19/2026		D(1)			693,750	(2)	01/01/2036	Common Stock	693,750	(1)	0	D
Stock Option (Right to Buy)	$1.13	03/19/2026		D(1)			638,000	(2)	03/03/2035	Common Stock	638,000	(1)	0	D
Stock Option (Right to Buy)	$0.97	03/19/2026		D(1)			543,750	(2)	01/01/2034	Common Stock	543,750	(1)	0	D
Stock Option (Right to Buy)	$0.838	03/19/2026		D(1)			181,250	(2)	11/19/2033	Common Stock	181,250	(1)	0	D
Stock Option (Right to Buy)	$1.21	03/19/2026		D(1)			211,500	(2)	03/19/2033	Common Stock	211,500	(1)	0	D
Stock Option (Right to Buy)	$2.16	03/19/2026		D(1)			211,500	(2)	12/06/2032	Common Stock	211,500	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			176,667	(2)	01/05/2032	Common Stock	176,667	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			100,000	(2)	09/16/2031	Common Stock	100,000	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			60,000	(2)	02/25/2031	Common Stock	60,000	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			47,667	(2)	02/14/2030	Common Stock	47,667	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			96,667	(2)	03/25/2029	Common Stock	96,667	(1)	0	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		693,750		(2)	01/01/2036	Common Stock	693,750	(1)	693,750	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		638,000		(2)	03/03/2025	Common Stock	638,000	(1)	638,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		543,750		(2)	01/01/2034	Common Stock	543,750	(1)	543,750	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		181,250		(2)	11/19/2033	Common Stock	181,250	(1)	181,250	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		211,500		(2)	03/19/2033	Common Stock	211,500	(1)	211,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		211,500		(2)	12/06/2032	Common Stock	211,500	(1)	211,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		176,667		(2)	01/05/2032	Common Stock	176,667	(1)	176,667	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		100,000		(2)	09/15/2031	Common Stock	100,000	(1)	100,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		60,000		(2)	02/25/2031	Common Stock	60,000	(1)	60,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		47,667		(2)	02/14/2030	Common Stock	47,667	(1)	47,667	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		96,667(1)		(2)	03/25/2029	Common Stock	96,667	(1)	96,667	D

Explanation of Responses:

1. Effective as of March 19, 2026 (the "Repricing Date"), the Issuer approved a one-time repricing of certain outstanding stock options (the "Repriced Options") granted under the Issuer's 2019 Incentive Award Plan (the "2019 Plan"), which reduced the per share exercise price of each Repriced Option to $0.45 (the "Option Repricing"). Except as modified by the Option Repricing, all other terms and conditions of the Repriced Options, including, without limitation, any provisions with respect to vesting and term of the Repriced Options, remain in full force and effect.

2. This stock option award was issued pursuant to the 2019 Plan and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

Remarks:

	/s/ Jeff Boerneke, Attorney-in-Fact	03/20/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider activity did Gossamer Bio (GOSS) report for Bryan Giraudo?

Gossamer Bio reported that COO/CFO Bryan Giraudo had multiple existing stock option grants canceled and reissued on March 19, 2026. The company implemented a one-time repricing, lowering the exercise price on these options while leaving vesting schedules and other terms under the 2019 Incentive Award Plan unchanged.

Did Bryan Giraudo buy or sell Gossamer Bio common stock in this Form 4?

No common stock was bought or sold. The Form 4 shows only derivative transactions in stock options, classified as dispositions to the issuer and grant or award acquisitions. These are compensation-related adjustments and do not represent open-market purchases or sales of Gossamer Bio common shares.

What exercise price were Gossamer Bio options repriced to in this filing?

All affected stock options were repriced to an exercise price of $0.45 per share. Previously, the options carried higher exercise prices ranging from $0.838 to $2.88. The repricing applies to options granted under Gossamer Bio’s 2019 Incentive Award Plan and became effective March 19, 2026.

Were vesting terms changed in Gossamer Bio’s option repricing for Bryan Giraudo?

Vesting terms were not changed. The company states that, apart from reducing the exercise price to $0.45 per share, all other terms and conditions of the repriced options, including vesting provisions and the remaining term, continue in full force under the original award agreements.

What does the Form 4 say about the plan governing Gossamer Bio’s repriced options?

The repriced options were issued under Gossamer Bio’s 2019 Incentive Award Plan. The Form 4 notes that the one-time repricing applied to certain outstanding options granted under this plan, and that the awards continue to vest according to the schedules previously reported in earlier Form 4 filings.

How many types of option transactions are reported for Bryan Giraudo in this Form 4?

The filing reports two types of option transactions: dispositions to the issuer (code D) of existing stock options and grant or award acquisitions (code A) of replacement stock options. Together they represent an option repricing, with no reported exercises, gifts, or tax-withholding transactions.