Fund tied to Sionna director sells 115,844 shares
Sionna Therapeutics director-affiliated fund reports planned share sale.
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Form Type
4
Rhea-AI Filing Summary
Sionna Therapeutics director-affiliated fund reports planned share sale. OrbiMed Private Investments VIII LP, an entity associated with director Peter A. Thompson, sold 115,844 shares of Sionna Therapeutics common stock in an open-market transaction at $45.50 per share under a Rule 10b5-1 trading plan. Following this sale, 2,555,877 shares of Sionna common stock are reported as indirectly held, with OrbiMed-related entities and the reporting person disclaiming beneficial ownership beyond any pecuniary interest.
Insider Trade Summary 10b5-1
Net Seller: 115,844 shares
Net Sell
1 txn
Insider
Thompson Peter A.
Role
Director
Sold
115,844 shs ($5.27M)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Sale | Common Stock | 115,844 | $45.50 | $5.27M |
Holdings After Transaction:
Common Stock — 2,555,877 shares (Indirect, See footnotes)
Footnotes (3)
- F1. These securities were sold pursuant to a 10b5-1 plan.
- F2. These securities are held of record by OrbiMed Private Investments VIII, LP ("OPI VIII"). OrbiMed Capital GP VIII LLC ("GP VIII") is the general partner of OPI VIII and OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of GP VIII. By virtue of such relationships, GP VIII and OrbiMed Advisors may be deemed to have voting and investment power with respect to the shares held by OPI VIII and as a result may be deemed to have beneficial ownership of such shares. OrbiMed Advisors exercises investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VIII. The Reporting Person is a member of OrbiMed Advisors.
- F3. Each of the Reporting Person, OrbiMed Advisors, and GP VIII disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
Key Figures
Shares sold: 115,844 shares
Sale price per share: $45.50 per share
Shares held after sale: 2,555,877 shares
+1 more
4 metrics
Shares sold
115,844 shares
Open-market sale of common stock on June 30, 2026
Sale price per share
$45.50 per share
Price for the 115,844 shares sold
Shares held after sale
2,555,877 shares
Indirect holdings reported following the transaction
Net shares sold in filing
115,844 shares
Net selling activity, as transactionSummary shows net-sell
Key Terms
Rule 10b5-1 plan, beneficial ownership, pecuniary interest, Section 16, +1 more
5 terms
Rule 10b5-1 plan regulatory
"These securities were sold pursuant to a 10b5-1 plan."
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
beneficial ownership regulatory
"may be deemed to have beneficial ownership of such shares."
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
pecuniary interest financial
"except to the extent of its pecuniary interest therein, if any."
Section 16 regulatory
"beneficial owner of such securities for purposes of Section 16 of the Exchange Act"
Section 16 is a U.S. securities law rule that governs the trading and disclosure obligations of company insiders — typically officers, directors and large shareholders — to promote transparency and deter unfair profit-taking. It requires insiders to publicly report their stock trades and allows companies or the issuer to reclaim quick, short-term profits from certain insider trades, like a scoreboard and a refund policy that help investors see and limit possible insider advantage.
voting and investment power financial
"may be deemed to have voting and investment power with respect to the shares"
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What insider transaction did Sionna Therapeutics (SION) report in this Form 4?
Sionna Therapeutics reported that OrbiMed Private Investments VIII LP, associated with director Peter A. Thompson, sold 115,844 shares of common stock. The sale was an open-market transaction at $45.50 per share executed under a Rule 10b5-1 trading plan.
Was the Sionna Therapeutics (SION) insider sale made under a Rule 10b5-1 plan?
Yes. The filing notes that the securities were sold pursuant to a Rule 10b5-1 trading plan. Such plans are pre-arranged programs that allow insiders or affiliated entities to systematically sell shares according to predetermined instructions, reducing discretion over trade timing.
AI-generated analysis. How Rhea-AI works. Not financial advice.
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