MBX
MBX Biosciences, Inc. Common Stock · Healthcare · Biotechnology
Momentum inputs (comparable managers):
holder breadth — ·
share flow — ·
net new positions +20.0%
— formula
Broad accumulation — rising shares across more holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q3 2024
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 67 | +5 | 22.03M | $1.22B | +10 | −5 |
| Q1 2026 | 65 | +3 | 17.55M | $523.43M | +9 | −6 |
| Q4 2025 | 61 | +2 | 15.34M | $483.77M | +2 | — |
| Q3 2025 | 15 | +2 | 13.00M | $227.48M | +2 | — |
| Q2 2025 | 10 | -1 | 8.10M | $92.45M | +1 | −2 |
| Q1 2025 | 8 | 0 | 4.62M | $34.08M | +2 | −2 |
| Q4 2024 | 8 | -2 | 5.08M | $93.07M | — | −2 |
| Q3 2024 | 9 | +9 | 4.81M | $122.94M | +9 | — |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | Wellington Management ✦ | 2.94M | New | $74.26M | 0.0% | New | 1 | SEC ↗ |
| 2 | Wellington Management ✦ | 2.94M | New | $74.26M | 0.0% | New | 1 | SEC ↗ |
| 3 | Wellington Management ✦ | 2.94M | New | $74.26M | 0.0% | New | 1 | SEC ↗ |
| 4 | Wellington Management ✦ | 2.94M | New | $74.26M | 0.0% | New | 1 | SEC ↗ |
| 5 | T. Rowe Price ✦ | 1.19M | New | $30.99M | 0.0% | New | 1 | SEC ↗ |
| 6 | Millennium Management ✦ | 440.41K | New | $11.44M | 0.0% | New | 1 | SEC ↗ |
| 7 | Citadel Advisors ✦ | 135.61K | New | $3.52M | 0.0% | New | 1 | SEC ↗ |
| 8 | Citadel Advisors ✦ | 135.61K | New | $3.52M | 0.0% | New | 1 | SEC ↗ |
| 9 | Soros Fund Management ✦ | 30.00K | New | $779,400 | 0.0% | New | 1 | SEC ↗ |
| 10 | Norges Bank ✦ (passive) | 25.00K | New | $649,500 | 0.0% | New | 1 | SEC ↗ |
| 11 | Geode Capital Management ✦ (passive) | 22.27K | New | $578,548 | 0.0% | New | 1 | SEC ↗ |
| 12 | Point72 Asset Management ✦ | 15.60K | New | $405,288 | 0.0% | New | 1 | SEC ↗ |
| 13 | Marshall Wace ✦ | 12.00K | New | $311,760 | 0.0% | New | 1 | SEC ↗ |
| 14 | Marshall Wace ✦ | 12.00K | New | $311,760 | 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
| Wellington Management | $74.26M | 0.0% |
| Wellington Management | $74.26M | 0.0% |
| Wellington Management | $74.26M | 0.0% |
| Wellington Management | $74.26M | 0.0% |
| T. Rowe Price | $30.99M | 0.0% |
| Millennium Management | $11.44M | 0.0% |
| Citadel Advisors | $3.52M | 0.0% |
| Citadel Advisors | $3.52M | 0.0% |
| Soros Fund Management | $779,400 | 0.0% |
| Norges Bank | $649,500 | 0.0% |
| Geode Capital Management | $578,548 | 0.0% |
| Point72 Asset Management | $405,288 | 0.0% |
Exited
| No tracked exits this quarter. |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 156 holders, 52.39M shares, $1.53B 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.