Upstream Bio Inc
UPB
83 hedge funds and large institutions have $531M invested in Upstream Bio Inc 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.
215% more repeat investments, than reductions
Existing positions increased: 41 | Existing positions reduced: 13
99% more capital invested
Capital invested by funds: $267M → $531M (+$264M)
40% more first-time investments, than exits
New positions opened: 14 | Existing positions closed: 10
5% more funds holding
Funds holding: 79 → 83 (+4)
3.61% more ownership
Funds ownership: 86.28% → 89.89% (+3.6%)
0% more funds holding in top 10
Funds holding in top 10: 4 → 4 (0)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Vanguard Group
Malvern,
Pennsylvania
|
+$11.7M |
| 2 |
BlackRock
New York
|
+$8.41M |
| 3 |
Fidelity Investments
Boston,
Massachusetts
|
+$6.29M |
| 4 |
PHP
Parkman Healthcare Partners
Stamford,
Connecticut
|
+$4.45M |
| 5 |
Geode Capital Management
Boston,
Massachusetts
|
+$2.18M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
AllianceBernstein
Nashville,
Tennessee
|
-$9.85M |
| 2 |
DTC
Deep Track Capital
Greenwich,
Connecticut
|
-$7.91M |
| 3 |
SB
Samsara BioCapital
Palo Alto,
California
|
-$5.76M |
| 4 |
Wellington Management Group
Boston,
Massachusetts
|
-$814K |
| 5 |
Millennium Management
New York
|
-$378K |
UPB Hedge Fund Activity: Q2 2025 in Review
83 of the 7,595 institutional investors tracked by Wall St. Rank reported a position in Upstream Bio Inc (UPB) for Q2 2025, worth a combined $531M — up 99% from $267M a quarter earlier.
Buyers outnumbered sellers: 14 funds opened new UPB positions and 10 closed out — a net gain of 4 holders — while 41 added to existing stakes and 13 trimmed.
The largest buyer was Vanguard Group, adding an estimated $11.7M. The largest seller was AllianceBernstein, cutting an estimated $9.85M.
- 83 institutional investors held Upstream Bio Inc (UPB) as of Q2 2025, up from 79 in Q1 2025.
- Funds reported $531M of Upstream Bio Inc stock for Q2 2025, up 99% quarter-over-quarter.
- 14 funds opened new Upstream Bio Inc positions in Q2 2025 and 10 closed out, a net change of +4 holders.
- The largest Upstream Bio Inc buyer in Q2 2025 was Vanguard Group, an estimated $11.7M added.
- The largest Upstream Bio Inc seller in Q2 2025 was AllianceBernstein, an estimated $9.85M sold.
Based on aggregated 13F filings for Q2 2025.