Upstream Bio Inc
UPB
148 hedge funds and large institutions have $350M invested in Upstream Bio Inc in 2026 Q2 according to their latest regulatory filings, with 37 funds opening new positions, 65 increasing their positions, 28 reducing their positions, and 28 closing their positions.
2,580% more call options, than puts
Call options by funds: $268K | Put options by funds: $10K
132% more repeat investments, than reductions
Existing positions increased: 65 | Existing positions reduced: 28
32% more first-time investments, than exits
New positions opened: 37 | Existing positions closed: 28
10.45% more ownership
Funds ownership: 82.48% → 92.93% (+10%)
6% more funds holding
Funds holding: 140 → 148 (+8)
0% more funds holding in top 10
Funds holding in top 10: 2 → 2 (0)
13% less capital invested
Capital invested by funds: $404M → $350M (-$54.4M)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
JP Morgan Chase
New York
|
+$4.6M |
| 2 |
Walleye Capital
New York
|
+$4.18M |
| 3 |
AQR Capital Management
Greenwich,
Connecticut
|
+$3.96M |
| 4 |
BNP Paribas Financial Markets
Paris,
France
|
+$3.23M |
| 5 |
BlackRock
New York
|
+$3.21M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Federated Hermes
Pittsburgh,
Pennsylvania
|
-$8.82M |
| 2 |
Pictet Asset Management
Carouge,
Switzerland
|
-$6.6M |
| 3 |
HSBC Holdings
London,
United Kingdom
|
-$5.27M |
| 4 |
NCM
Nantahala Capital Management
New Canaan,
Connecticut
|
-$3.6M |
| 5 |
SB
Samsara BioCapital
Palo Alto,
California
|
-$3.2M |
UPB Hedge Fund Activity: Q2 2026 in Review
148 of the 8,349 institutional investors tracked by Wall St. Rank reported a position in Upstream Bio Inc (UPB) for Q2 2026, worth a combined $350M — down 13% from $404M a quarter earlier.
Buyers outnumbered sellers: 37 funds opened new UPB positions and 28 closed out — a net gain of 9 holders — while 65 added to existing stakes and 28 trimmed.
The largest buyer was JP Morgan Chase, adding an estimated $4.6M. The largest seller was Federated Hermes, exiting entirely with an estimated $8.82M sold.
- 148 institutional investors held Upstream Bio Inc (UPB) as of Q2 2026, up from 140 in Q1 2026.
- Funds reported $350M of Upstream Bio Inc stock for Q2 2026, down 13% quarter-over-quarter.
- 37 funds opened new Upstream Bio Inc positions in Q2 2026 and 28 closed out, a net change of +9 holders.
- The largest Upstream Bio Inc buyer in Q2 2026 was JP Morgan Chase, an estimated $4.6M added.
- The largest Upstream Bio Inc seller in Q2 2026 was Federated Hermes, an estimated $8.82M sold.
Based on aggregated 13F filings for Q2 2026.