Upstream Bio Inc
UPB
95 hedge funds and large institutions have $836M invested in Upstream Bio Inc in 2025 Q3 according to their latest regulatory filings, with 22 funds opening new positions, 38 increasing their positions, 22 reducing their positions, and 10 closing their positions.
1,443% more call options, than puts
Call options by funds: $8.02M | Put options by funds: $520K
120% more first-time investments, than exits
New positions opened: 22 | Existing positions closed: 10
73% more repeat investments, than reductions
Existing positions increased: 38 | Existing positions reduced: 22
25% more funds holding in top 10
Funds holding in top 10: 4 → 5 (+1)
14% more funds holding
Funds holding: 83 → 95 (+12)
7.41% less ownership
Funds ownership: 89.89% → 82.48% (-7.4%)
42% less capital inflows, than outflows
Capital inflows: $66.1M | Capital outflows: $114M
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
State Street
Boston,
Massachusetts
|
+$9.8M |
| 2 |
Marshall Wace
London,
United Kingdom
|
+$8.97M |
| 3 |
Integral Health Asset Management
New York
|
+$8.93M |
| 4 |
BlackRock
New York
|
+$7.88M |
| 5 |
Vanguard Group
Malvern,
Pennsylvania
|
+$4.22M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Altshuler Shaham
Tel Aviv,
Israel
|
-$30.7M |
| 2 |
VR Adviser
New York
|
-$17.5M |
| 3 |
Deep Track Capital
Greenwich,
Connecticut
|
-$15.8M |
| 4 |
TCG Crossover Management
Palo Alto,
California
|
-$10.6M |
| 5 |
Omega Fund Management
Boston,
Massachusetts
|
-$10.6M |
UPB Hedge Fund Activity: Q3 2025 in Review
95 of the 7,655 institutional investors tracked by Wall St. Rank reported a position in Upstream Bio Inc (UPB) for Q3 2025, worth a combined $836M — up 58% from $531M a quarter earlier.
Buyers outnumbered sellers: 22 funds opened new UPB positions and 10 closed out — a net gain of 12 holders — while 38 added to existing stakes and 22 trimmed.
The largest buyer was State Street, adding an estimated $9.8M. The largest seller was Altshuler Shaham, cutting an estimated $30.7M.
- 95 institutional investors held Upstream Bio Inc (UPB) as of Q3 2025, up from 83 in Q2 2025.
- Funds reported $836M of Upstream Bio Inc stock for Q3 2025, up 58% quarter-over-quarter.
- 22 funds opened new Upstream Bio Inc positions in Q3 2025 and 10 closed out, a net change of +12 holders.
- The largest Upstream Bio Inc buyer in Q3 2025 was State Street, an estimated $9.8M added.
- The largest Upstream Bio Inc seller in Q3 2025 was Altshuler Shaham, an estimated $30.7M sold.
Based on aggregated 13F filings for Q3 2025.