SION
Sionna Therapeutics, Inc. · Healthcare · Market cap $187.6M
Insiders sold $40.5M net in the last 90 days ·4 sellers, 0 buyers· 5 of 6 sales under Rule 10b5-1 plans· latest Form 4 filed Sep 21, 2026
Insider Buying
$0
reported purchases (SEC code P)
Insider Selling
$165.9M
reported sales (SEC code S)
Unique Insiders
5
in the rolling window
Latest filing
Sep 21, 2026
RA CAPITAL MANAGEMENT, L.P.
Sionna Therapeutics, Inc. (SION) has 32 SEC Form 4 filings (101 transaction rows) in the rolling window, disclosed by 5 distinct insiders. Most recent filing: Sep 21, 2026.
Inside the rolling window, 5 insiders at Sionna Therapeutics, Inc. reported no open-market purchases and 52 open-market sales totaling $165.9M. The most active filer is Director Thompson Peter A. with 20 filings. Insiders have net sold $118.1M over the trailing 6 months. The most recent open-market filing is a sale of 3,448,811 shares by Director, 10% Owner RA CAPITAL MANAGEMENT, L.P., dated Sep 17, 2026, worth $21.8M.
- Industry:Biotechnology
- CEO:Michael Cloonan
- Employees:59
- HQ:Waltham, MA, US
- IPO:2025-02-07
| Source | |||||||
|---|---|---|---|---|---|---|---|
| Director, 10% Owner | Sale | 3,448,811 | $21.8M | Sep 21 | -30.8% | SEC ↗ | |
| Director | Sale | 85,918 | $3.9M | Jul 9 | -90.8% | SEC ↗ | |
| Director | Sale | 85,918 | $3.9M | Jul 9 | -90.8% | SEC ↗ | |
Fitzpatrick JenniferFirst in 4 months | Chief Legal Officer | Sale | 10,250 | $447K | Jul 7 | -90.8% | SEC ↗ |
| Director | Sale | 115,844 | $5.3M | Jul 2 | -90.6% | SEC ↗ | |
| Director | Sale | 115,844 | $5.3M | Jul 2 | -90.6% | SEC ↗ | |
| Director | Sale | 101 | $4K | May 30 | -89.9% | SEC ↗ | |
| Director | Sale | 101 | $4K | May 30 | -89.9% | SEC ↗ | |
| Director | Sale | 48,546 | $2.2M | May 11 | -91.0% | SEC ↗ | |
| Director | Sale | 59,767 | $2.7M | May 11 | — | SEC ↗ | |
| Director | Sale | 184,639 | $8.5M | May 11 | — | SEC ↗ | |
| Director | Sale | 48,546 | $2.2M | May 11 | — | SEC ↗ | |
| Director | Sale | 59,767 | $2.7M | May 11 | — | SEC ↗ | |
| Director | Sale | 184,639 | $8.5M | May 11 | — | SEC ↗ | |
| Director | Sale | 52,397 | $2.3M | Apr 21 | — | SEC ↗ | |
| Director | Sale | 2,948 | $131K | Apr 21 | — | SEC ↗ | |
| Director | Sale | 52,397 | $2.3M | Apr 21 | — | SEC ↗ | |
| Director | Sale | 2,948 | $131K | Apr 21 | — | SEC ↗ | |
| Director | Sale | 47,814 | $2.1M | Apr 16 | — | SEC ↗ | |
| Director | Sale | 235,863 | $10.5M | Apr 16 | — | SEC ↗ | |
| Director | Sale | 226,906 | $10.3M | Apr 16 | — | SEC ↗ | |
| Director | Sale | 47,814 | $2.1M | Apr 16 | — | SEC ↗ | |
| Director | Sale | 235,863 | $10.5M | Apr 16 | — | SEC ↗ | |
| Director | Sale | 226,906 | $10.3M | Apr 16 | — | SEC ↗ | |
| Chief Legal Officer | Sale | 10,250 | $347K | Mar 6 | — | SEC ↗ |
Earnings: last 7 quarters
Frequently asked questions
How many SEC Form 4 insider filings does SION have?
Sionna Therapeutics, Inc. (SION) has 32 SEC Form 4 filings (101 transaction rows) in the rolling 365-day window, disclosed by 5 distinct insiders. Most recent filing: Sep 21, 2026.
When was the most recent SEC Form 4 filing for SION?
The most recent Form 4 filing for SION on Tracefour is dated Sep 21, 2026.
Who is the most active insider at SION?
The most active SEC Form 4 filer at SION in the rolling window is Director Thompson Peter A., with 20 filings.
What is the net insider flow at SION over the last 6 months?
Over the trailing 180 days, insiders at SION have net sold $118.1M based on SEC Form 4 disclosures.
What is the total insider buy and sell value at SION in the current window?
Inside the rolling window, insiders at SION bought $0 and sold $165.9M based on SEC Form 4 filings.
Can I get alerts for SION insider trading?
Yes. Tracefour sends a free email when a new SEC Form 4 purchase or sale is filed at Sionna Therapeutics, Inc. (SION). Alerts are set per company from the page itself, there is no paid tier, and each email links to the original filing on SEC EDGAR.
Related companies
Sionna Therapeutics, Inc. is in the Healthcare sector.