Sionna Therapeutics, Inc.

SION

Exchange: Nasdaq
Industry: Pharmaceutical Preparations
SEC CIK: 0002036042

SEC filings (opens in a new tab)

In the last 90 days, Sionna Therapeutics, Inc. insiders filed 0 open-market purchases and 2 sales; 146 institutions reported holding it in 13F filings for Q2 2026, worth $2.11B in total; Viking Global Investors is the only superinvestor holding it.

Q1 2026 vs. Q4 2025

How the institutions holding Sionna Therapeutics, Inc. changed between Q4 2025 and Q1 2026.

All holders in Q1 2026 All holders in Q4 2025

13F holders of SION: Q4 2025 compared with Q1 2026
Measure	Q4 2025	Of which not filed for Q1 2026	Q1 2026	Change
Holders	101	2	122	+23
Shares	44.0M	1.19M	45.4M	+2.65M (+6.2%)
Value	$1.81B	$48.9M	$1.82B	+$56.2M (+3.2%)

2 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so the changes leave them out.

New holders (32)

Institutions that held Sionna Therapeutics, Inc. at the end of Q1 2026 but not at the end of Q4 2025.

Institutions new to SION in Q1 2026
Institution	Shares	Value	% of portfolio
Vanguard Capital Management LLC	1,029,497	$41.3M	0.00%
Sio Capital Management, LLC	294,340	$11.8M	1.70%
Candriam Luxembourg S.C.A.	236,813	$9.49M	0.05%
Adage Capital Partners GP, L.L.C.	150,000	$6.01M	0.01%
Vanguard Portfolio Management LLC	142,081	$5.70M	0.00%
Point72 Asset Management, L.P.	136,549	$5.47M	0.01%
GordonMD Global Investments LP	136,000	$5.45M	4.49%
Vanguard Fiduciary Trust Co	112,175	$4.50M	0.00%
Rhenman & Partners Asset Management AB	87,500	$3.51M	0.43%
Integral Health Asset Management, LLC	50,000	$2.00M	0.11%
Ishara Investments LP	49,200	$1.97M	1.99%
Qube Research & Technologies Ltd	42,242	$1.69M	0.00%
StemPoint Capital LP	36,540	$1.46M	0.28%
Maven Securities LTD	25,000	$1.00M	0.06%
Walleye Capital LLC	15,097	$605.2K	0.00%
Vanguard Global Advisers, LLC	11,191	$448.6K	0.00%
Susquehanna International Group, LLP	7,310	$293.1K	0.00%
ExodusPoint Capital Management, LP	7,190	$288.2K	0.00%
VARCOV Co.	6,571	$263.4K	0.10%
Quarry LP	6,304	$252.7K	0.05%
Hudson Bay Capital Management LP	6,180	$247.8K	0.00%
STRS Ohio	2,900	$116.3K	0.00%
Zurcher Kantonalbank (Zurich Cantonalbank)	371	$14.9K	0.00%
Steward Partners Investment Advisory, LLC	254	$10.2K	0.00%
Quantbot Technologies LP	178	$7.14K	0.00%
UBS Asset Management Americas Inc	116	$4.65K	0.00%
Caitong International Asset Management Co., Ltd	36	$1.44K	0.00%
Signaturefd, LLC	24	$962	0.00%
Fortitude Family Office, LLC	15	$601	0.00%
Root Financial Partners, LLC	10	$401	0.00%
MAI Capital Management	2	$81	0.00%
Covestor Ltd	3	$0	0.00%

Sold out (9)

Institutions that held Sionna Therapeutics, Inc. at the end of Q4 2025 and filed for Q1 2026 without it.

Institutions that sold out of SION in Q1 2026
Institution	Shares, Q4 2025	Value, Q4 2025
SG Americas Securities, LLC	10,691	$440.0K
American Century Companies Inc	6,180	$254.2K
Dark Forest Capital Management LP	5,991	$246.5K
D. E. Shaw & Co., Inc.	5,742	$236.2K
ProShare Advisors LLC	4,903	$201.7K
Balyasny Asset Management LLC	1,406	$57.8K
Amalgamated Bank	504	$21.0K
Daiwa Securities Group Inc.	149	$6.00K
Aster Capital Management (DIFC) Ltd	37	$1.52K

Not filed for Q1 2026 yet (2)

Institutions that held Sionna Therapeutics, Inc. at the end of Q4 2025 and haven't filed a 13F for Q1 2026. Not filing isn't selling, so they aren't counted as sold out.

Institutions holding SION in Q4 2025 that haven't filed for Q1 2026
Institution	Shares, Q4 2025	Value, Q4 2025
Vanguard Group Inc	1,184,951	$48.7M
CIBC Private Wealth Group, LLC	4,500	$185.1K