Fairmount Funds Management LLC - 06 Oct 2025 SCHEDULE 13D/A Report for Jade Biosciences, Inc. Common Stock, $0.0001 par value (JBIO)

Filing Manager
Fairmount Funds Management LLC
Reporting Manager
Fairmount Funds Management LLC
Security
Jade Biosciences, Inc. Common Stock, $0.0001 par value
Symbol
JBIO
Shares outstanding
51.8M shares
Disclosed Ownership
10.4M shares
Ownership
20%
Form type
SCHEDULE 13D/A
Filing time
08 Oct 2025, 16:15:29 UTC
Date of event
06 Oct 2025
Previous filing
01 May 2025
SEC
View on sec.gov

Reporting Managers (5)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
Fairmount Funds Management LLC 19.99% 10.4M 0 10.4M /s/ Peter Harwin Peter Harwin, Managing Member 0001802528
Fairmount Healthcare Fund II L.P. 14.86% 7.7M 0 7.7M /s/ Peter Harwin Peter Harwin, Managing Member 0001769651
Fairmount Healthcare Co-Invest IV L.P. 5.77% 2.66M 0 2.66M /s/ Peter Harwin Peter Harwin, Managing Member 0002042283
Peter Evan Harwin 19.99% 10.4M 0 10.4M /s/ Peter Harwin Peter Harwin 0001663607
Tomas Kiselak 19.99% 10.4M 0 10.4M /s/ Tomas Kiselak Tomas Kiselak 0001830177