Upstream Bio, Inc.
UPB- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0002022626
In the last 90 days, Upstream Bio, Inc. insiders filed 0 open-market purchases and 5 sales; 148 institutions reported holding it in 13F filings for Q2 2026, worth $350.1M in total; no superinvestor holds it.
13F holders, Q3 2025
Institutional positions in Upstream Bio, Inc. as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 95
- +13 vs. Q2 2025
- Shares held
- 44.5M
- −2.92M (−6.2%) vs. Q2 2025
- Total value
- $836.3M
- +$316.1M (+60.7%) vs. Q2 2025
- New holders
- 22
- 38 more added
- Sold out
- 9
- 22 more reduced
1 institution that held it in Q2 2025 haven't filed for Q3 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q2 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting UPB on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 148 | $350.1M |
| Q1 2026 | 140 | $404.5M |
| Q4 2025 | 133 | $1.39B |
| Q3 2025 | 95 | $836.3M |
| Q2 2025 | 83 | $530.9M |
| Q1 2025 | 79 | $266.9M |
| Q4 2024 | 70 | $690.1M |
| Q3 2024 | 0 | $0 |
| Q2 2024 | 0 | $0 |
| Q1 2024 | 0 | $0 |
| Q4 2023 | 0 | $0 |
| Q3 2023 | 0 | $0 |
| Q2 2023 | 0 | $0 |
| Q1 2023 | 0 | $0 |
| Q4 2022 | 0 | $0 |
| Q3 2022 | 0 | $0 |
| Q2 2022 | 0 | $0 |
| Q1 2022 | 0 | $0 |
| Q4 2021 | 0 | $0 |
| Q3 2021 | 0 | $0 |
| Q2 2021 | 0 | $0 |
| Q1 2021 | 0 | $0 |
Institutions, Q3 2025
Shares, value and share of portfolio for each institution holding Upstream Bio, Inc.; share changes are against Q2 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| STRS Ohio | 0 | $0 | 0.00% | −1,800−100.0% | Sold out |
| Caitong International Asset Management Co., Ltd | 0 | $0 | 0.00% | −224−100.0% | Sold out |
| True Wealth Design, LLC | 0 | $0 | 0.00% | −31−100.0% | Sold out |
| Advisor Group Holdings, Inc. | 0 | $0 | 0.00% | −42−100.0% | Sold out |
| Norges Bank | – | – | – | – | Not filed |