Upstream Bio, Inc.: which funds bought and sold
Institutions that bought and sold Upstream Bio shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.
Between March 31, 2026 and June 30, 2026, 100 institutions that filed 13F reports for both quarters added to or opened positions in Upstream Bio, and 56 cut or closed them. Together they added a net 1.9M shares, +4.3% on what they held at the start of the quarter. Active managers and hedge funds on our list were net buyers of 2.1M shares (+14.3%); index fund managers were net buyers of 470K shares (+5.6%). 36 opened a new position and 28 sold out entirely.
Bought, Q2 2026 100 institutions, 36 of them new holders Sold, Q2 2026 56 institutions, 28 of them sold out
Net change, all compared +1.9M shares (+4.3%)
Net change, active managers +2.1M shares (+14.3%), 27 bought, 11 sold
Buyers versus sellers
100 bought 18 56 sold
Active managers and hedge funds 27 bought · 11 sold · +2.1M
Index fund managers 7 bought · 2 sold · +470K
Other institutions 66 bought · 43 sold · −670K
Biggest buyers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Jpmorgan Chase & Co | +549K +118.6% | 1.0M | $7M |
| Walleye Capital LLC Hedge fund | +498K New position | 498K | $3.4M |
| AQR Capital Management LLC Hedge fund | +473K +655.0% | 545K | $3.8M |
| BNP Paribas Financial Markets | +386K +306.0% | 512K | $3.5M |
| Blackrock, Inc. Index funds | +383K +11.4% | 3.8M | $26M |
| Qube Research & Technologies Ltd Hedge fund | +359K +58.0% | 979K | $6.8M |
| Bank Of America Corp | +343K +708.4% | 392K | $2.7M |
| Dimensional Fund Advisors LP | +302K +377.0% | 382K | $2.6M |
| Trexquant Investment LP Hedge fund | +290K +164.0% | 466K | $3.2M |
| Voleon Capital Management LP Hedge fund | +285K New position | 285K | $2M |
| Point72 Asset Management, L.P. Hedge fund | +275K +154.3% | 453K | $3.1M |
| Jacobs Levy Equity Management, Inc Active manager | +253K New position | 253K | $1.8M |
| Squarepoint Ops LLC Hedge fund | +246K +551.9% | 291K | $2M |
| D. E. Shaw & Co., Inc. Hedge fund | +216K +26.3% | 1.0M | $7.2M |
| Millennium Management LLC Hedge fund | +206K +22.0% | 1.1M | $7.9M |
| Acadian Asset Management LLC Active manager | +175K New position | 175K | $1.2M |
| Arrowstreet Capital, Limited Partnership Hedge fund | +173K +93.3% | 358K | $2.5M |
| HRT Financial LP | +171K New position | 171K | $1.2M |
| Parkman Healthcare Partners LLC | +148K +18.9% | 935K | $6.5M |
| Algert Global LLC Hedge fund | +119K New position | 119K | $820,920 |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Walleye Capital LLC Hedge fund | +498K New position | 498K | $3.4M |
| AQR Capital Management LLC Hedge fund | +473K +655.0% | 545K | $3.8M |
| Qube Research & Technologies Ltd Hedge fund | +359K +58.0% | 979K | $6.8M |
| Trexquant Investment LP Hedge fund | +290K +164.0% | 466K | $3.2M |
| Voleon Capital Management LP Hedge fund | +285K New position | 285K | $2M |
| Point72 Asset Management, L.P. Hedge fund | +275K +154.3% | 453K | $3.1M |
| Jacobs Levy Equity Management, Inc Active manager | +253K New position | 253K | $1.8M |
| Squarepoint Ops LLC Hedge fund | +246K +551.9% | 291K | $2M |
| D. E. Shaw & Co., Inc. Hedge fund | +216K +26.3% | 1.0M | $7.2M |
| Millennium Management LLC Hedge fund | +206K +22.0% | 1.1M | $7.9M |
Biggest sellers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Federated Hermes, Inc. Active manager | −980K Sold out | 0 | — |
| Pictet Asset Management Holding SA | −733K Sold out | 0 | — |
| HSBC Holdings PLC | −630K −98.3% | 11K | $77,602 |
| Nantahala Capital Management, LLC Hedge fund | −400K Sold out | 0 | — |
| Samsara Biocapital, LLC | −382K −51.9% | 354K | $2.4M |
| Y-Intercept (Hong Kong) Ltd | −307K −30.7% | 694K | $4.8M |
| Alyeska Investment Group, L.P. Hedge fund | −298K Sold out | 0 | — |
| Bain Capital Life Sciences Investors, LLC | −266K −30.7% | 601K | $4.2M |
| Prosight Management, LP | −241K Sold out | 0 | — |
| Tcg Crossover Management, LLC | −181K Sold out | 0 | — |
| Sphera Funds Management Ltd. | −138K −38.6% | 220K | $1.5M |
| Jump Financial, LLC | −96K −30.1% | 223K | $1.5M |
| Goldman Sachs Group Inc | −70K −22.0% | 247K | $1.7M |
| Marshall Wace, LLP Hedge fund | −67K Sold out | 0 | — |
| Exoduspoint Capital Management, LP Hedge fund | −50K −55.1% | 41K | $284,031 |
| ADAR1 Capital Management, LLC Hedge fund | −35K Sold out | 0 | — |
| Aquatic Capital Management LLC | −31K Sold out | 0 | — |
| Bleakley Financial Group, LLC | −29K Sold out | 0 | — |
| Morgan Stanley | −28K −5.1% | 525K | $3.6M |
| Tudor Investment Corp Et Al Hedge fund | −26K Sold out | 0 | — |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Federated Hermes, Inc. Active manager | −980K Sold out | 0 | — |
| Nantahala Capital Management, LLC Hedge fund | −400K Sold out | 0 | — |
| Alyeska Investment Group, L.P. Hedge fund | −298K Sold out | 0 | — |
| Marshall Wace, LLP Hedge fund | −67K Sold out | 0 | — |
| Exoduspoint Capital Management, LP Hedge fund | −50K −55.1% | 41K | $284,031 |
| ADAR1 Capital Management, LLC Hedge fund | −35K Sold out | 0 | — |
| Tudor Investment Corp Et Al Hedge fund | −26K Sold out | 0 | — |
| Martingale Asset Management L P Active manager | −26K Sold out | 0 | — |
| Victory Capital Management Inc Active manager | −26K Sold out | 0 | — |
| Franklin Resources Inc Active manager | −15K Sold out | 0 | — |
New positions
| Institution | Shares | Value June 30, 2026 |
|---|---|---|
| Walleye Capital LLCHedge fund | 498K | $3.4M |
| Voleon Capital Management LPHedge fund | 285K | $2M |
| Jacobs Levy Equity Management, IncActive manager | 253K | $1.8M |
| Acadian Asset Management LLCActive manager | 175K | $1.2M |
| HRT Financial LP | 171K | $1.2M |
| Algert Global LLCHedge fund | 119K | $820,920 |
| Brevan Howard Capital Management LPHedge fund | 50K | $348,553 |
| Allspring Global Investments Holdings, LLC | 43K | $298,819 |
| Two Sigma Investments, LPHedge fund | 42K | $292,889 |
| Nverses Capital, LLC | 24K | $166,280 |
Sold out
| Institution | Shares | Value March 31, 2026 |
|---|---|---|
| Federated Hermes, Inc.Active manager | 980K | $8.8M |
| Pictet Asset Management Holding SA | 733K | $6.6M |
| Nantahala Capital Management, LLCHedge fund | 400K | $3.6M |
| Alyeska Investment Group, L.P.Hedge fund | 298K | $2.7M |
| Prosight Management, LP | 241K | $2.2M |
| Tcg Crossover Management, LLC | 181K | $1.6M |
| Marshall Wace, LLPHedge fund | 67K | $600,930 |
| ADAR1 Capital Management, LLCHedge fund | 35K | $315,000 |
| Aquatic Capital Management LLC | 31K | $283,356 |
| Bleakley Financial Group, LLC | 29K | $259,776 |
Who holds the shares
- Institutions reporting
- 148
- Ten largest holders
- 62.5% of 13F-reported shares
- Index fund managers
- 17.6% of 13F-reported shares
- Active managers and hedge funds
- 33.5% of 13F-reported shares
| Type | Bought | Sold | New | Sold out | Net change in shares | Net % |
|---|---|---|---|---|---|---|
| Active managers and hedge funds | 27 | 11 | 12 | 9 | +2.1M | +14.3% |
| Index fund managers | 7 | 2 | 0 | 0 | +470K | +5.6% |
| Other institutions | 66 | 43 | 24 | 19 | −670K | −3.1% |