SION
Sionna Therapeutics, Inc. · 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 Q1 2025
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 60 | +8 | 16.87M | $740.62M | +10 | −2 |
| Q1 2026 | 54 | +1 | 14.59M | $579.96M | +6 | −5 |
| Q4 2025 | 53 | 0 | 13.47M | $554.19M | +2 | −2 |
| Q3 2025 | 15 | +3 | 10.71M | $314.89M | +3 | — |
| Q2 2025 | 9 | -1 | 5.91M | $102.50M | +1 | −2 |
| Q1 2025 | 8 | +8 | 4.63M | $48.42M | +8 | — |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | Viking Global Investors ✦ | 2.95M | New | $30.89M | 0.1% | New | 1 | SEC ↗ |
| 2 | T. Rowe Price ✦ | 996.21K | New | $10.42M | 0.0% | New | 1 | SEC ↗ |
| 3 | T. Rowe Price ✦ | 996.21K | New | $10.42M | 0.0% | New | 1 | SEC ↗ |
| 4 | Citadel Advisors ✦ | 326.50K | New | $3.42M | 0.0% | New | 1 | SEC ↗ |
| 5 | Millennium Management ✦ | 179.07K | New | $1.87M | 0.0% | New | 1 | SEC ↗ |
| 6 | Geode Capital Management ✦ (passive) | 135.56K | New | $1.42M | 0.0% | New | 1 | SEC ↗ |
| 7 | Geode Capital Management ✦ (passive) | 135.56K | New | $1.42M | 0.0% | New | 1 | SEC ↗ |
| 8 | State Street Global Advisors ✦ (passive) | 14.40K | New | $150,624 | 0.0% | New | 1 | SEC ↗ |
| 9 | Marshall Wace ✦ | 12.19K | New | $127,486 | 0.0% | New | 1 | SEC ↗ |
| 10 | Marshall Wace ✦ | 12.19K | New | $127,486 | 0.0% | New | 1 | SEC ↗ |
| 11 | Two Sigma Investments ✦ | 11.71K | New | $122,539 | 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
| Viking Global Investors | $30.89M | 0.1% |
| T. Rowe Price | $10.42M | 0.0% |
| T. Rowe Price | $10.42M | 0.0% |
| Citadel Advisors | $3.42M | 0.0% |
| Millennium Management | $1.87M | 0.0% |
| Geode Capital Management | $1.42M | 0.0% |
| Geode Capital Management | $1.42M | 0.0% |
| State Street Global Advisors | $150,624 | 0.0% |
| Marshall Wace | $127,486 | 0.0% |
| Marshall Wace | $127,486 | 0.0% |
| Two Sigma Investments | $122,539 | 0.0% |
Exited
| No tracked exits this quarter. |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 121 holders, 43.94M shares, $1.73B 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.