UPB
Upstream Bio, Inc. · Healthcare · Biotechnology
Momentum inputs (comparable managers):
holder breadth +16.7% ·
share flow +14.8% ·
net new positions +7.1%
· formula
Broad accumulation: rising shares across more holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q3 2025
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | Fidelity (FMR) ✦ | 8.09M | +1.9% | $152.11M | 0.0% | ▲ Add | 2 | SEC ↗ ×5 |
| 2 | BlackRock ✦ (passive) | 2.60M | +24.2% | $48.98M | 0.0% | ▲ Add | 2 | SEC ↗ ×9 |
| 3 | The Vanguard Group ✦ (passive) | 2.44M | +12.5% | $45.94M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
| 4 | Wellington Management ✦ | 1.13M | -8.2% | $21.17M | 0.0% | ▼ Trim | 4 | SEC ↗ ×2 |
| 5 | State Street Global Advisors ✦ (passive) | 1.11M | +131.5% | $20.97M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 6 | Marshall Wace ✦ | 868.00K | +198.8% | $16.33M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 7 | Geode Capital Management ✦ (passive) | 817.11K | +26.4% | $15.37M | 0.0% | ▲ Add | 4 | SEC ↗ ×2 |
| 8 | Goldman Sachs Group ✦ | 223.21K | n/a | $4.20M | 0.0% | n/c | 1 | SEC ↗ |
| 9 | Morgan Stanley ✦ | 87.53K | n/a | $1.65M | 0.0% | n/c | 1 | SEC ↗ ×4 |
| 10 | JPMorgan Chase ✦ | 59.89K | n/a | $1.13M | 0.0% | n/c | 1 | SEC ↗ ×4 |
| 11 | Millennium Management ✦ | 40.11K | New | $754,526 | 0.0% | New | 1 | SEC ↗ |
| 12 | AQR Capital Management ✦ | 29.95K | +0.7% | $563,434 | 0.0% | ▲ Add | 3 | SEC ↗ ×5 |
| 13 | T. Rowe Price ✦ | 18.50K | +6.0% | $349,000 | 0.0% | ▲ Add | 2 | SEC ↗ |
| 14 | Two Sigma Investments ✦ | 10.50K | New | $197,505 | 0.0% | New | 1 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value: the conviction measure. ✦ = curated manager.
New buyers
| Millennium Management | $754,526 | 0.0% |
| Two Sigma Investments | $197,505 | 0.0% |
Exited
| Norges Bank | $10.65M | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 140 holders, 44.42M shares, $399.81M reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
What else this security's tracked holders most often hold: shared-ownership counts, not fundamental relationships.
Open-market purchases (P)
No open-market insider purchases in our coverage window.
Open-market sales (S)
Officer · 485 sh · $2,663
Officer · 895 sh · $4,914
Officer · 853 sh · $4,683
Officer · 700 sh · $3,843
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology