Upstream Bio, Inc.

Historical 13F Holders

Symbol: UPB
CUSIP: 91678A107
All holders as of: Q2 2026
Type: Equity
Class: COM

Reported Value, Excluding Options

Total Shares Held, Excluding Options

Total Filers

13D/G Filers

Each filer's latest filing for 91678A107 since 12/18/2024, largest first.

Filer	% of Class	Shares	Form	Filed
Norges Bank 13G/A	7.7%	4,206,586	13G/A	8/12/2026 Event 6/30/2026
FMR LLC 13G/A	6.9%	3,793,955	13G/A	11/6/2026 Event 10/30/2026
FMR LLC	6.9%	3,793,955
Abigail P. Johnson	6.9%	3,793,955
BlackRock, Inc. 13G	5.2%	2,814,714	13G	7/30/2026 Event 6/30/2026
Under 5%, checked the "5 percent or less" box, or amended by a later filing (3)
Decheng Capital Global Life Sciences Fund IV, L.P. 13G/A	4.9%	2,724,868	13G/A	10/29/2026 Event 9/30/2026
Decheng Capital Global Life Sciences Fund IV, L.P.	4.9%	2,724,868
Decheng Capital Management IV (Cayman), LLC	4.9%	2,724,868
Xiangmin Cui	4.9%	2,724,868
HBM Healthcare Investments (Cayman) Ltd. 13G/A	4.1%	2,195,111	13G/A	11/14/2025 Event 9/30/2025
TCG Crossover GP I, LLC 13G/A	3.9%	2,117,103	13G/A	11/14/2025 Event 9/30/2025
TCG Crossover GP I, LLC	3.9%	2,117,103
TCG Crossover Fund I, L.P.	3.9%	2,117,103
Chen Yu	3.9%	2,117,103

13F Holders by Quarter

Period	Filers	Shares, Excl. Options	Value, Excl. Options	Options Value
2026 Q3	50	12.8 M	$67.6M	$0
2026 Q2	150	50.6 M	$350M	$256k
2026 Q1	143	44.9 M	$404M	$1.36M
2025 Q4	135	51.2 M	$1.39B	$2.16M
2025 Q3	99	44.5 M	$836M	$8.05M
2025 Q2	84	48.4 M	$531M	$0
2025 Q1	80	46.3 M	$267M	$0
2024 Q4	71	42.1 M	$690M	$0