Form 4: Sionna Therapeutics: Atlas Venture Funds Report Beneficial Ownership Changes Following IPO

Atlas Venture Funds report changes in beneficial ownership of Sionna Therapeutics common stock following the company's initial public offering.

Summary

• Atlas Venture Fund XI, L.P. reports changes in beneficial ownership of Sionna Therapeutics (SION) common stock.
• The changes are a result of the automatic conversion of preferred stock into common stock upon the closing of Sionna Therapeutics' IPO on February 10, 2025.
• Atlas Venture Opportunity Fund II, L.P. also reports changes in beneficial ownership, including the acquisition of 60,000 shares of common stock at $18 per share.
• The reporting entities include Atlas Venture Fund XI, L.P., Atlas Venture Associates XI, L.P., Atlas Venture Associates XI, LLC, Atlas Venture Opportunity Fund II, L.P., Atlas Venture Associates Opportunity II, L.P., and Atlas Venture Associates Opportunity II, LLC.

Sentiment

Score: 7

Explanation: The document reflects a routine filing following a successful IPO, indicating a positive event for the company and its investors. The sentiment is neutral to positive.

Positives

• The successful completion of the IPO triggered the conversion of preferred stock to common stock, simplifying the capital structure.
• Atlas Venture Opportunity Fund II, L.P. increased its holdings in Sionna Therapeutics through a purchase of common stock.

Future Outlook

The document does not contain specific forward-looking statements regarding Sionna Therapeutics' future performance.

Industry Context

Form 4 filings are standard practice after significant events like IPOs, providing transparency into the ownership structure of publicly traded companies.

Key Dates