MBX
MBX Biosciences, Inc. Common Stock · Healthcare · Biotechnology
Momentum inputs (comparable managers):
holder breadth -20.0% ·
share flow +2.6% ·
net new positions -20.0%
— formula
Concentrated accumulation — rising shares among fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q4 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 ✦ | 2.91M | -1.0% | $52.99M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 2 | Wellington Management ✦ | 2.91M | -1.0% | $52.99M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 3 | Wellington Management ✦ | 2.91M | -1.0% | $52.99M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 4 | Wellington Management ✦ | 2.91M | -1.0% | $52.99M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 5 | T. Rowe Price ✦ | 1.16M | -2.6% | $21.41M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 6 | T. Rowe Price ✦ | 1.16M | -2.6% | $21.41M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 7 | Millennium Management ✦ | 333.64K | -24.2% | $6.15M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 8 | Geode Capital Management ✦ (passive) | 265.70K | +1093.2% | $4.90M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 9 | Geode Capital Management ✦ (passive) | 265.70K | +1093.2% | $4.90M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 10 | Citadel Advisors ✦ | 220.33K | +62.5% | $4.06M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 11 | State Street Global Advisors ✦ (passive) | 142.65K | — | $2.63M | 0.0% | n/c | 1 | SEC ↗ |
| 12 | Marshall Wace ✦ | 25.90K | +115.8% | $477,339 | 0.0% | ▲ Add | 2 | SEC ↗ |
| 13 | Marshall Wace ✦ | 25.90K | +115.8% | $477,339 | 0.0% | ▲ Add | 2 | SEC ↗ |
| 14 | Norges Bank ✦ (passive) | 25.00K | 0.0% | $460,750 | 0.0% | Held | 2 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| No new tracked buyers this quarter. |
Exited
| Soros Fund Management | $779,400 | was 0.0% |
| Point72 Asset Management | $405,288 | was 0.0% |
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.