UPB

Upstream Bio, Inc. Common Stock
UPB

Overview Fund Activity

82 hedge funds and large institutions have $531M invested in Upstream Bio, Inc. Common Stock in 2025 Q2 according to their latest regulatory filings, with 14 funds opening new positions, 41 increasing their positions, 13 reducing their positions, and 10 closing their positions.

New
Increased
Maintained
Reduced
Closed
Holders
82
Holders Change
+4
Holders Change %
+5.13%
% of All Funds
1.1%
Holding in Top 10
4
Holding in Top 10 Change
–
Holding in Top 10 Change %
–
% of All Funds
0.05%
New
14
Increased
41
Reduced
13
Closed
10
Calls
–
Puts
–
Net Calls
–
Net Calls Change
–

Top Buyers

1
Vanguard Group
Vanguard Group
Pennsylvania
$23.8M
2
BlackRock
BlackRock
New York
$23M
3
Fidelity Investments
Fidelity Investments
Massachusetts
$87.1M
4
PHP
Parkman Healthcare Partners
Connecticut
$7.86M
5
Geode Capital Management
Geode Capital Management
Massachusetts
$7.1M

Top Sellers

1
AllianceBernstein
AllianceBernstein
Tennessee
$270K
2
DTC
Deep Track Capital
Connecticut
$15.8M
3
SB
Samsara BioCapital
California
$15.8M
4
Wellington Management Group
Wellington Management Group
Massachusetts
$13.5M
5
Millennium Management
Millennium Management
New York
$0
Name Holding Trade Value Shares
Change 		Shares
Change %
Fidelity Investments
1
Fidelity Investments
Massachusetts
$87.1M +$7.48M +681,021 +9%
O
2
OrbiMed
New York
$62.5M – – –
AS
3
Altshuler Shaham
Israel
$37.3M +$1.75M +159,148 +5%
DC
4
Decheng Capital
California
$36.1M – – –
TCM
5
TCG Crossover Management
California
$30.8M – – –
ES
6
Enavate Sciences
California
$27M – – –
BCLSI
7
Bain Capital Life Sciences Investors
Massachusetts
$26.8M +$1.58M +144,216 +6%
VA
8
VR Adviser
New York
$25.2M – – –
Vanguard Group
9
Vanguard Group
Pennsylvania
$23.8M +$13.9M +1,263,807 +139%
BlackRock
10
BlackRock
New York
$23M +$10M +910,738 +77%
OFM
11
Omega Fund Management
Massachusetts
$22.4M – – –
SB
12
Samsara BioCapital
California
$15.8M -$6.85M -623,915 -30%
DTC
13
Deep Track Capital
Connecticut
$15.8M -$9.41M -856,800 -37%
Wellington Management Group
14
Wellington Management Group
Massachusetts
$13.5M -$968K -88,162 -7%
Norges Bank
15
Norges Bank
Norway
$10.6M +$10.6M +969,916 New
SL
16
Siren LLC
Connecticut
$8.66M – – –
PHP
17
Parkman Healthcare Partners
Connecticut
$7.86M +$5.29M +481,941 +206%
Geode Capital Management
18
Geode Capital Management
Massachusetts
$7.1M +$2.59M +235,958 +57%
NCM
19
Nantahala Capital Management
Connecticut
$6.53M – – –
WP
20
Woodline Partners
California
$6.13M +$13.1K +1,189 +0.2%
State Street
21
State Street
Massachusetts
$5.29M +$2.04M +185,788 +63%
SSA
22
Schonfeld Strategic Advisors
New York
$4.02M +$2.06M +187,806 +106%
GPP
23
Great Point Partners
Connecticut
$3.29M – – –
Marshall Wace
24
Marshall Wace
United Kingdom
$3.19M -$159K -14,437 -5%
UBS Group
25
UBS Group
Switzerland
$2.56M +$1.11M +101,336 +77%
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