Based on data from the past 90 days ending February 19, 2026, Sionna Therapeutics's three largest insider shareholders are TenPercentOwner Gp A, Llc Tpg (6.49Mn shares), TenPercentOwner Venture Fund Xi, L.P. Atlas (3.69Mn shares), Director Peter A. Thompson (3.53Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Gp A, Llc Tpg | 6,494,962 | 26 Jan, 2026 | |
| Venture Fund Xi, L.P. Atlas | 3,694,020 | 10 Feb, 2025 | |
| Advisors Llc Orbimed | 3,530,702 | 04 Feb, 2026 | |
| Peter A. Thompson | 3,530,702 | 04 Feb, 2026 | |
| Bruce Booth | 686,567 | 21 Oct, 2025 | |
| Michael Cloonan | President & Ceo | 547,343 | 22 Oct, 2025 |
| Capital Management, L.P. Ra | 159,033 | 24 Nov, 2025 | |
| Elena Ridloff | Cfo & Head Of Corp. Dev. | 38,532 | 03 Sep, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 03 Feb, 2026 | Advisors Llc Orbimed | Common Stock | D | 29,063 | $44.58 | 3,530,702 | I | S |
| 03 Feb, 2026 | Peter A. Thompson | Common Stock | D | 29,063 | $44.58 | 3,530,702 | I | S |
| 02 Feb, 2026 | Advisors Llc Orbimed | Common Stock | D | 1,890 | $44.57 | 3,559,765 | I | S |
| 02 Feb, 2026 | Peter A. Thompson | Common Stock | D | 1,890 | $44.57 | 3,559,765 | I | S |
| 22 Jan, 2026 | Gp A, Llc Tpg | Common Stock | D | 250,000 | $40.00 | 6,494,962 | I | S |
| 24 Dec, 2025 | Advisors Llc Orbimed | Common Stock | D | 33,356 | $44.55 | 3,561,655 | I | S |
| 24 Dec, 2025 | Peter A. Thompson | Common Stock | D | 33,356 | $44.55 | 3,561,655 | I | S |
| 19 Dec, 2025 | Advisors Llc Orbimed | Common Stock | D | 875 | $44.49 | 3,595,011 | I | S |
| 19 Dec, 2025 | Peter A. Thompson | Common Stock | D | 875 | $44.49 | 3,595,011 | I | S |
| 18 Dec, 2025 | Advisors Llc Orbimed | Common Stock | D | 100 | $44.49 | 3,595,886 | I | S |
| 18 Dec, 2025 | Peter A. Thompson | Common Stock | D | 100 | $44.49 | 3,595,886 | I | S |
| 17 Dec, 2025 | Advisors Llc Orbimed | Common Stock | D | 900 | $44.50 | 3,595,986 | I | S |
| 17 Dec, 2025 | Peter A. Thompson | Common Stock | D | 900 | $44.50 | 3,595,986 | I | S |
| 05 Dec, 2025 | Jennifer Fitzpatrick | Common Stock | D | 10,250 | $40.52 | 0 | D | S |
| 05 Dec, 2025 | Jennifer Fitzpatrick | Common Stock | A | 10,250 | $6.11 | 10,250 | D | M |
| 05 Dec, 2025 | Jennifer Fitzpatrick | - | - | 10,250 | D | |||
| 05 Dec, 2025 | Jennifer Fitzpatrick | - | - | 0 | D | |||
| 26 Nov, 2025 | Advisors Llc Orbimed | Common Stock | D | 1,600 | $44.49 | 3,596,886 | I | S |
| 26 Nov, 2025 | Peter A. Thompson | Common Stock | D | 1,600 | $44.49 | 3,596,886 | I | S |
| 25 Nov, 2025 | Advisors Llc Orbimed | Common Stock | D | 11,890 | $44.60 | 3,598,486 | I | S |