4

Changes in Ownership

Sionna Therapeutics, Inc. Filed 2025-02-10 Acc 0000950170-25-017030

10% owner bought 60,000 shares at $18.00 ($1,080,000)

10% owner acquired 3,634,020 shares (conversion)

From the SEC's structured data for this filing

Trades in this filing

Insider	Date	Transaction	Shares	Price	Value	Owned after	D/I
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion	+2,886,293			2,886,293	D
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion	+747,727			747,727	I
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Purchase	+60,000	$18.00	$1,080,000	807,727	I
Derivatives
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion · Series Seed convertible preferred stock	−1,051,051			0	D
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion · Series A convertible preferred stock	−1,806,317			0	D
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion · Series B convertible preferred stock	−1,298,332			0	D
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion · Series C convertible preferred stock	−61,463			0	D
Atlas Venture Fund XI, L.P. 10% owner	2025-02-10	Conversion · Series C convertible preferred stock	−1,092,504			0	I
Open-market purchases · 60,000 sh · avg $18.00 · $1,080,000