UPB Institutional Ownership
Who owns Upstream Bio, Inc. and what the big funds did with it last quarter, from every SEC 13F filing. 149 funds reported holding UPB at Jun 30, 2026, together owning 92.3% of the company.
- ▲102 buying vs 56 selling
- ▲Held by funds +10.4 pts
- ▲Funds holding +9
- ▲Superinvestors: 3 added, 0 cut
- ●Put/call not meaningful
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
7 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 149 | 140 | +6.4% |
| In funds' top 10 | 2 | 2 | 0.0% |
| 13F shares | 50.6M | 44.9M | +12.7% |
| Held by funds | 92.3% | 82.0% | +10.4 pts |
| New positions | 37 | 40 | −7.5% |
| Increased | 65 | 47 | +38.3% |
| Reduced | 28 | 35 | −20.0% |
| Sold out | 28 | 38 | −26.3% |
| Calls (shares) | 0 | 12K | −100.0% |
| Puts (shares) | 0 | 0 | – |
| Put/call ratio | – | 0.00 | – |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in UPB
All superinvestors →
Who owns UPB
share of fund held shares- Index and passive funds18.4%
- Active managers and hedge funds67.0%
- Banks and brokers6.9%
- Pensions, insurers and other7.7%
The top 10 holders own 62.5% of all UPB shares that funds reported. Groups are our own grouping of filers by name.
Put/call ratio
funds' options, market makers left outAbove 1 means funds hold more puts than calls, a sign of hedging or bets on a fall. Options are valued at the underlying shares.
Filed so far for Q3 2026
23 funds changed their position- Y-Intercept (Hong Kong) LtdTrimmed−51K sh
- Strs OhioAdded+19K sh
- Alps Advisors IncAdded+17K sh
- Wealth Enhancement Advisory Services, LLCSold out−10K sh
- Creative PlanningTrimmed−13K sh
🔒 Free account: see all 20.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | Fmr LLC | 14.90% | 8.2M | $56.5M | +61K |
| 2 | Orbimed Advisors LLC | 10.40% | 5.7M | $39.4M | 0 |
| 3 | Norges Bank | 6.88% | 3.8M | $26.1M | +3.8M |
| 4 | BlackRock, Inc. | 6.85% | 3.8M | $26M | +383K |
| 5 | Decheng Capital LLC | 4.98% | 2.7M | $18.9M | 0 |
| 6 | Enavate Sciences Gp, LLC | 4.49% | 2.5M | $17M | 0 |
| 7 | Vanguard Capital Management LLC | 3.43% | 1.9M | $13M | +3,160 |
| 8 | Millennium Management LLC | 2.09% | 1.1M | $7.9M | +206K |
| 9 | D. E. Shaw & Co., Inc. | 1.89% | 1M | $7.2M | +216K |
| 10 | Jpmorgan Chase & Co | 1.85% | 1M | $7M | +549K |
- Norges Bank+3.8M sh+$26.1M
- Jpmorgan Chase & Co+549K sh+$3.8M
- Walleye Capital LLC+498K sh+$3.4M
- AQR Capital Management LLC+473K sh+$3.3M
- Bnp Paribas Financial Markets+386K sh+$2.7M
- BlackRock, Inc.+383K sh+$2.6M
- Qube Research & Technologies Ltd+359K sh+$2.5M
- Bank of America Corp /de/+343K sh+$2.4M
- Federated Hermes, Inc.−980K sh−$8.8M
- Pictet Asset Management Holding SA−733K sh−$6.6M
- HSBC Holdings PLC−630K sh−$4.5M
- Nantahala Capital Management, LLC−400K sh−$3.6M
- Alyeska Investment Group, L.P.−298K sh−$2.7M
- Samsara Biocapital, LLC−382K sh−$2.6M
- Prosight Management, LP−241K sh−$2.2M
- Y-Intercept (Hong Kong) Ltd−307K sh−$2.1M
UPB institutional ownership FAQ
Who owns the most UPB stock?
In Q2 2026 13F filings the largest holder of UPB was Fmr LLC, followed by Orbimed Advisors LLC and Norges Bank. Index fund managers are usually the biggest holders of large companies.
What percentage of UPB is owned by institutions?
Funds that file 13F reports held 92.3% of UPB's shares at Jun 30, 2026, compared with 82.0% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying UPB?
In Q2 2026, 102 funds bought UPB (37 of them new positions) and 56 sold (28 sold out completely). Among well known investors, 3 added and 0 cut. Our fund sentiment for UPB is strongly bullish.
What is UPB's institutional put/call ratio?
Too few option positions were reported for a meaningful ratio.
How current is this UPB ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.