Consolidated Statements of Stockholders’ Equity (Deficit) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive income (loss)
Beginning balance (in shares) at Dec. 31, 2022		94,423,181
Beginning balance at Dec. 31, 2022	$ 12,077	$ 10	$ 1,044,864	$ (1,032,223)	$ (574)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with a private offering, net of offering costs (in shares)		129,869,440
Issuance of common stock in connection with a private offering, net of offering costs	$ 201,323	$ 13	201,310
Vesting of restricted stock (in shares)		55,225
Exercise of stock options (in shares)	0
Stock-based compensation	$ 28,518		28,518
Issuance of common stock pursuant to Employee Stock Purchase Plan (in shares)		336,795
Issuance of common stock pursuant to Employee Stock Purchase Plan	444		444
Issuance of common stock for restricted stock units vested (in shares)		724,674
Net loss	(179,817)			(179,817)
Other comprehensive income (loss)	224				224
Ending balance (in shares) at Dec. 31, 2023		225,409,315
Ending balance at Dec. 31, 2023	62,769	$ 23	1,275,136	(1,212,040)	(350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Grant of equity option pursuant to Chiesi Collaboration Agreement	$ 464		464
Exercise of stock options (in shares)	0
Stock-based compensation	$ 20,619		20,619
Issuance of common stock pursuant to Employee Stock Purchase Plan (in shares)		767,125
Issuance of common stock pursuant to Employee Stock Purchase Plan	629		629
Issuance of common stock for restricted stock units vested (in shares)		427,698
Net loss	(56,528)			(56,528)
Other comprehensive income (loss)	$ 1,539				1,539
Ending balance (in shares) at Dec. 31, 2024	226,604,138	226,604,138
Ending balance at Dec. 31, 2024	$ 29,492	$ 23	1,296,848	(1,268,568)	1,189
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Investment in merger option through issuance of stock (in shares)		2,500,000
Investment in merger option through issuance of stock	7,476	$ 1	7,475
Exercise of warrants (in shares)		1,791,823
Exercise of warrants	$ 3,655		3,655
Exercise of stock options (in shares)	1,691,213	1,691,213
Exercise of stock options	$ 1,930		1,930
Stock-based compensation	10,555		10,555
Issuance of common stock pursuant to Employee Stock Purchase Plan (in shares)		1,089,883
Issuance of common stock pursuant to Employee Stock Purchase Plan	840		840
Net loss	(170,370)			(170,370)
Other comprehensive income (loss)	$ (6,338)				(6,338)
Ending balance (in shares) at Dec. 31, 2025	233,677,057	233,677,057
Ending balance at Dec. 31, 2025	$ (122,760)	$ 24	$ 1,321,303	$ (1,438,938)	$ (5,149)

Gossamer Bio, Inc. 10-K