🕵️ Sionna Therapeutics, Inc. ($SION)
SEC insider & ownership activity, last 12 months · CIK 2036042 · every row links its SEC filing
Over the last 12 months insiders sold $174.6M with no open-market buying against it. Orbimed Advisors LLC sold $55.7M through a 10b5-1 trading plan in 20 lots (Nov–Jul). RA Capital Management, L.P. trimmed 23.7% → 22.6%; Peter Kolchinsky trimmed 23.7% → 22.6%. No red-flag 8-Ks in the window.
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Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
0 buyers, $0 (0 lots) · 8 sellers, $174.6M (158 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Orbimed Advisors LLC | 0 | – | 20 | $55.7M | Jul 7, 2026 |
| Peter A. Thompson | 0 | – | 20 | $55.7M | Jul 7, 2026 |
| Booth Bruce | 0 | – | 50 | $22.1M | Oct 21, 2025 |
| RA Capital Management, L.P. | 0 | – | 44 | $21.5M | Nov 21, 2025 |
| TPG GP A, LLC | 0 | – | 1 | $10.0M | Jan 22, 2026 |
| Michael Cloonan | 0 | – | 12 | $6.3M | Oct 21, 2025 |
| Ridloff Elena | 0 | – | 7 | $2.0M | Sep 2, 2025 |
| Jennifer Fitzpatrick | 0 | – | 4 | $1.4M | Jul 6, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| RA Capital Management, L.P. | 22.6% | 13D | Nov 5, 2025 | filing ↗ | |
| Peter Kolchinsky | 22.6% | 13D | Nov 5, 2025 | filing ↗ | |
| Rajeev Shah | 22.6% | 13D | Nov 5, 2025 | filing ↗ | |
| RA Capital Healthcare Fund, L.P. | 15.5% | 13D | Nov 5, 2025 | filing ↗ | |
| TPG GP A, LLC | 15.2% | 13D | Feb 10, 2025 | filing ↗ | |
| James G. Coulter | 15.2% | 13D | Feb 10, 2025 | filing ↗ | |
| Jon Winkelried | 15.2% | 13D | Feb 10, 2025 | filing ↗ | |
| Viking Global Investors LP | 7.1% | 13G | May 15, 2026 | filing ↗ | |
| Viking Global Opportunities Parent GP LLC | 7.1% | 13G | May 15, 2026 | filing ↗ | |
| Halvorsen Ole Andreas | 7.1% | 13G | May 15, 2026 | filing ↗ | |
| Shabet Rose Sharon | 7.1% | 13G | May 15, 2026 | filing ↗ | |
| David C. Ott | 6.7% | 13G | Feb 14, 2025 | filing ↗ | |
| Orbimed Advisors LLC | 6.6% | 13D | Apr 15, 2026 | filing ↗ | |
| Orbimed Capital GP VIII LLC | 6.6% | 13D | Apr 15, 2026 | filing ↗ | |
| Enavate Sciences GP, LLC | 5.6% | 13D | Feb 10, 2025 | filing ↗ | |
| Sionna Aggregator, LP | 5.6% | 13D | Feb 10, 2025 | filing ↗ | |
| Atlas Venture Associates XI, L.P. | 5.4% | 13D | Oct 16, 2025 | filing ↗ | |
| Atlas Venture Fund XI, L.P. | 5.4% | 13D | Oct 16, 2025 | filing ↗ | |
| Atlas Venture Associates XI, LLC | 5.4% | 13D | Oct 16, 2025 | filing ↗ | |
| RA Capital Nexus Fund III, L.P. | 5.0% | 13D | Nov 5, 2025 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Jennifer Fitzpatrick | $451K | Jul 6, 2026 | filing ↗ |
| Orbimed Private Investments VIII, LP | $9.0M | May 29, 2026 | filing ↗ |
| Jennifer Fitzpatrick | $354K | Mar 5, 2026 | filing ↗ |
| RISE Fund Sling, L.P. | $8.2M | Jan 22, 2026 | filing ↗ |
| RISE Fund Sling II, L.P. | $2.3M | Jan 22, 2026 | filing ↗ |
| Jennifer R Fitzpatrick | $419K | Dec 5, 2025 | filing ↗ |
| Orbimed Private Investments VIII, LP | $46.5M | Nov 24, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $53K | Nov 21, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $281K | Nov 21, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $433K | Nov 21, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $332K | Nov 21, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $51K | Nov 20, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $79K | Nov 20, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $10K | Nov 20, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $60K | Nov 20, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $89K | Nov 19, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $551K | Nov 19, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $718K | Nov 19, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $466K | Nov 19, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $82K | Nov 18, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $107K | Nov 18, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $69K | Nov 18, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $13K | Nov 18, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $989K | Nov 17, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $1.3M | Nov 17, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $837K | Nov 17, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $157K | Nov 17, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $675K | Oct 28, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $143K | Oct 28, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $1.2M | Oct 28, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $413K | Oct 28, 2025 | filing ↗ |
| RA Capital Nexus Fund, L.P. | $4.8M | Oct 24, 2025 | filing ↗ |
| RA Capital Nexus Fund III, L.P. | $2.6M | Oct 24, 2025 | filing ↗ |
| RA Capital Healthcare Fund LP | $553K | Oct 24, 2025 | filing ↗ |
| Blackwell Partners LLC - Series A | $4.2M | Oct 24, 2025 | filing ↗ |
| Michael Cloonan | $3.2M | Oct 21, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $496K | Oct 21, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $2.4M | Oct 21, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $1.5M | Oct 20, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $310K | Oct 20, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $347K | Oct 17, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $1.7M | Oct 17, 2025 | filing ↗ |
| Michael Cloonan | $6K | Oct 16, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $4.3M | Oct 16, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $908K | Oct 16, 2025 | filing ↗ |
| Michael Cloonan | $748K | Oct 15, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $15K | Oct 14, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $3K | Oct 14, 2025 | filing ↗ |
| Atlas Venture Fund XI, LP | $1.4M | Oct 13, 2025 | filing ↗ |
| Atlas Venture Opportunity Fund II, L.P. | $297K | Oct 13, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Shareholder vote (5.07) | Jun 17, 2026 | filing ↗ |
| Earnings (2.02) | May 12, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 12, 2026 | filing ↗ |
| Earnings (2.02) | Mar 2, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 2, 2026 | filing ↗ |
| Earnings (2.02) | Nov 5, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 5, 2025 | filing ↗ |
| Earnings (2.02) | Aug 11, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 11, 2025 | filing ↗ |