Gossamer Bio, Inc.

GOSS·NASDAQ·$0.22Share Price as of 11/2·$52MMarket Cap as of 11/2

Financials

10-QQ2 ended 06/30/2608/13/26 10-QQ1 ended 03/31/2605/15/26 10-KFY 202503/17/26 10-QQ3 ended 09/30/2511/05/25 10-QQ2 ended 06/30/2508/05/25

Disclosures

8-KCurrent report10/28/26 8-KCurrent report09/28/26 8-KCurrent report09/23/26 8-KCurrent report09/16/26 8-KCurrent report09/11/26

Prospectuses and Registrations

POS AMPost-effective amendment03/17/26 POSASRProspectus / registration03/17/26 S-3ASRAutomatic shelf registration01/28/26 S-8Registration of securities for employees03/13/25 S-8Registration of securities for employees03/05/24

Proxies

DEF 14ADefinitive proxy09/16/26 PRE 14APreliminary proxy09/03/26 DEF 14ADefinitive proxy06/09/26 DEFA14AAdditional proxy materials05/18/26 PRE 14APreliminary proxy05/18/26

Ownership

SC 13D/ABeneficial ownership (amended)10/29/26 SC 13D/ABeneficial ownership (amended)10/08/26 SC 13D/ABeneficial ownership (amended)09/28/26 Form 4Insider transaction09/25/26 Form 4Insider transaction09/25/26

Other

DD09/04/26 ARSAnnual report to shareholders04/24/26 EFFECTRequest for effectiveness03/18/26 ARSAnnual report to shareholders04/29/25 ARSAnnual report to shareholders04/26/24