October 3, 2025 · Form 4 insider transaction
Booth Bruce sold 31,198 shares of Sionna Therapeutics, Inc. at $30.00 per share, a transaction worth $935.9K. The trade was recorded as open-market sale under a pre-scheduled Rule 10b5-1 plan and disclosed on an SEC Form 4, filed 4 days after the transaction.
This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.; The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (6).; These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.