Sionna Therapeutics, Inc. Common Stock (SION)
Who owns Sionna Therapeutics, Inc. Common Stock (SION)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 36.7% of the shares are freely tradable; institutional investors hold 100.3%.
Ownership Structure
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| RA Capital Management, LLC | 21.94 | 9,905,045 | +0.0 | 03/31/2026 |
| TPG GP A, LLC | 14.39 | 6,494,962 | -3.7 | 03/31/2026 |
| Orbimed Advisors, LLC | 7.82 | 3,530,702 | -0.9 | 03/31/2026 |
| Viking Global Investors LP | 7.08 | 3,195,181 | +0.0 | 03/31/2026 |
| Atlas Venture Life Science Advisors, LLC | 6.63 | 2,995,602 | +0.0 | 03/31/2026 |
| Enavate Sciences GP, LLC | 5.49 | 2,478,030 | +0.0 | 03/31/2026 |
| JPMorgan Chase & Co | 3.24 | 1,465,014 | +18.9 | 03/31/2026 |
| Jennison Associates LLC | 3.21 | 1,451,220 | +30.1 | 03/31/2026 |
| BlackRock Inc | 2.87 | 1,295,867 | +0.3 | 03/31/2026 |
| Vanguard Group Inc | 2.62 | 1,184,951 | +3.7 | 12/31/2025 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 7. Jul 2026 | Thompson Peter A. | Director | Sell | 85,918 | 44.86 | 3,854,281 |
| 7. Jul 2026 | Orbimed Advisors Llc | Director | Sell | 85,918 | 44.86 | 3,854,281 |
| 18. Apr 2026 | Orbimed Advisors Llc | Director | Sell | 2,948 | 44.52 | 131,245 |
| 18. Apr 2026 | Peter A Thompson | Director | Sell | 2,948 | 44.52 | 131,245 |
| 17. Apr 2026 | Orbimed Advisors Llc | Director | Sell | 52,397 | 44.68 | 2,341,098 |
| 17. Apr 2026 | Peter A Thompson | Director | Sell | 52,397 | 44.68 | 2,341,098 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character.
View all insider transactions →Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.