Sionna Therapeutics's top three insider shareholders as of March 23, 2026 are Venture Fund Xi, L.P. Atlas (TenPercentOwner, 3.69Mn shares), Peter A. Thompson (Director, 3.53Mn shares), Michael Cloonan (President Ceo, 547.34K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Venture Fund Xi, L.P. Atlas | 2,886,293 | 807,727 | 10 Feb, 2025 | |
| Peter A. Thompson | 0 | 3,530,702 | 04 Feb, 2026 | |
| Michael Cloonan | President Ceo | 547,343 | 0 | 22 Oct, 2025 |
| Elena Ridloff | Cfo Head Of Corp. Dev. | 38,532 | 0 | 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 |
|---|---|---|---|---|---|---|---|---|
| 05 Mar, 2026 | Jennifer Fitzpatrick | Common Stock | A | 10,250 | $6.11 | 10,250 | D | M |
| 05 Mar, 2026 | Jennifer Fitzpatrick | Common Stock | D | 10,250 | $33.86 | 0 | D | S |
| 05 Mar, 2026 | Jennifer Fitzpatrick | Non-Qualified Stock Option (right to buy) | D | 10,250 | $0.00 | 50,935 | D | M |
| 02 Feb, 2026 | Peter A. Thompson | Common Stock | D | 1,890 | $44.57 | 3,559,765 | I | S |
| 03 Feb, 2026 | Peter A. Thompson | Common Stock | D | 29,063 | $44.58 | 3,530,702 | I | S |
| 02 Jan, 2026 | Jennifer Fitzpatrick | Non-Qualified Stock Option (right to buy) | A | 103,140 | $0.00 | 103,140 | D | A |
| 02 Jan, 2026 | Charlotte Mckee | Non-Qualified Stock Option (right to buy) | A | 155,700 | $0.00 | 155,700 | D | A |
| 02 Jan, 2026 | Elena Ridloff | Non-Qualified Stock Option (right to buy) | A | 165,440 | $0.00 | 165,440 | D | A |
| 02 Jan, 2026 | Caroline Stark Beer | Non-Qualified Stock Option (right to buy) | A | 139,340 | $0.00 | 139,340 | D | A |
| 02 Jan, 2026 | Michael Cloonan | Non-Qualified Stock Option (right to buy) | A | 436,100 | $0.00 | 436,100 | D | A |
| 24 Dec, 2025 | Peter A. Thompson | Common Stock | D | 33,356 | $44.55 | 3,561,655 | I | S |
| 17 Dec, 2025 | Peter A. Thompson | Common Stock | D | 900 | $44.50 | 3,595,986 | I | S |
| 18 Dec, 2025 | Peter A. Thompson | Common Stock | D | 100 | $44.49 | 3,595,886 | I | S |
| 19 Dec, 2025 | Peter A. Thompson | Common Stock | D | 875 | $44.49 | 3,595,011 | I | S |
| 05 Dec, 2025 | Jennifer Fitzpatrick | Common Stock | A | 10,250 | $6.11 | 10,250 | D | M |
| 05 Dec, 2025 | Jennifer Fitzpatrick | Common Stock | D | 10,250 | $40.52 | 0 | D | S |
| 05 Dec, 2025 | Jennifer Fitzpatrick | Non-Qualified Stock Option (right to buy) | D | 10,250 | $0.00 | 61,185 | D | M |
| 24 Nov, 2025 | Peter A. Thompson | Common Stock | D | 94,583 | $44.54 | 3,610,376 | I | S |
| 25 Nov, 2025 | Peter A. Thompson | Common Stock | D | 11,890 | $44.60 | 3,598,486 | I | S |
| 26 Nov, 2025 | Peter A. Thompson | Common Stock | D | 1,600 | $44.49 | 3,596,886 | I | S |