TCG Crossover GP I, LLC - Sep 30, 2025 SCHEDULE 13G/A Report for Upstream Bio, Inc. Common Stock, par value $0.001 per share (UPB)

Filing Manager
TCG Crossover GP I, LLC
Reporting Manager
TCG Crossover GP I, LLC
Security
Upstream Bio, Inc. Common Stock, par value $0.001 per share
Symbol
UPB
Shares outstanding
54.3M shares
Disclosed Ownership
2.12M shares
Ownership
3.9%
Form type
SCHEDULE 13G/A
Date filed
11/14/2025, 04:27 PM
Date of event
Sep 30, 2025
Previous filing
Feb 14, 2025
SEC
View on sec.gov

Reporting Managers (3)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
TCG Crossover GP I, LLC 3.9% 2.12M 0 2.12M /s/ Craig Skaling Authorized Signatory
TCG Crossover Fund I, L.P. 3.9% 2.12M 0 2.12M /s/ Craig Skaling Authorized Signatory
Chen Yu 3.9% 2.12M 0 2.12M /s/ Craig Skaling By POA as Attorney-in-Fact