Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share (SION)

Q: What does CUSIP 829401108 represent in this 13F holders report?

CUSIP 829401108 is the security identifier for SION - Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share used to aggregate holder disclosures.

Q: How many institutions held SION - Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share in Q2 2026?

2 institutional investors reported SION - Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share for Q2 2026. Use the holders table for investor-level position and value details.

CUSIP: 829401108

Q2 2026 13F Holders as of 30 Jun 2026

Security type / class: Equity / Common Stock, $0.001 par value per share
Total 13F shares: 250
Total 13F value: $10,998
Share change: +12
SEC-reported price per share: $44.00
Number of holders: 2
Value change: +$528
Number of buys: 2
Shares outstanding: 45,002,549

Security key

829401108

Report period

Q2 2026

Institutions

Top holders

SION full security history Ownership snapshot Full 13F holder table Previous quarter: Q1 2026 Sionna Therapeutics, Inc. SEC filings Sionna Therapeutics, Inc. company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Reporting periods

Holder history for CUSIP 829401108

Previous quarter: Q1 2026

Recent filing periods:

Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025

Ownership snapshot

Top reported holders of SION - Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader

RA CAPITAL MANAGEMENT, L.P.

Disclosed value leader

RA CAPITAL MANAGEMENT, L.P.

Comparable rows

15/15

Latest evidence

31 Mar 2026

13F 13D/G 3/4/5 Lead comparable stake: 23% 13D/G row: RA CAPITAL MANAGEMENT, L.P. Showing 1-6 of 15 holder rows.

Quick read

RA CAPITAL MANAGEMENT, L.P. leads the comparable SEC ownership view at 23%.

15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens RA CAPITAL MANAGEMENT, L.P.'s linked filing trail.

Comparable ownership Top 5

RA CAPITAL MANAGEMENT, L.P. 23%

TPG GP A, LLC 15%

VIKING GLOBAL INVESTORS LP 7.1%

ORBIMED ADVISORS LLC 6.6%

Enavate Sciences GP, LLC 5.6%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-6 of 15 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
RA CAPITAL MANAGEMENT, L.P.	13F 13D/G 3/4/5 Company · Director, 10%+ Owner 13F 13D/G 3/4/5	23% from 13D/G	$397,093,254 9,905,045 shares	—	31 Mar 2026
TPG GP A, LLC	13F 13D/G 3/4/5 Company · 10%+ Owner 13F 13D/G 3/4/5	15% from 13D/G	$260,383,027 6,494,962 shares	—	31 Mar 2026
VIKING GLOBAL INVESTORS LP	13D/G 13F Company 13D/G 13F	7.1%	$133,462,710 3,195,181 shares	+$10,126,176	31 Mar 2026
ORBIMED ADVISORS LLC	13F 13D/G Company 13F 13D/G	6.6% from 13D/G	$141,545,843 3,530,702 shares	—	31 Mar 2026
Enavate Sciences GP, LLC	13F 13D/G Company 13F 13D/G	5.6% from 13D/G	$99,344,223 2,478,030 shares	—	31 Mar 2026
Atlas Venture Fund XI, L.P.	13D/G 3/4/5 10%+ Owner 13D/G 3/4/5	5.4%	$74,744,824 2,382,495 shares	-$15,805,403	16 Oct 2025

How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

13F holder rows

Institutional holders as of Q2 2026

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions

250

Rows available

Investor	Option	Weight %	Change %	SEC-reported value	* Price	Shares	Share Change	Activity	Report Period

^* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.

Compare Q2 2026 vs Q1 2026 Across Filers

Q1 2026 holders

121

Q2 2026 holders

Holder diff

-119

Investor	Q1 2026 Shares	Q2 2026 Shares	Share Diff	Share Chg %	Q1 2026 value	Q2 2026 value	Value change	Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend