Sionna Therapeutics SION Institutional Ownership

NASDAQ SION

$5.11 -0.15 (-2.76%)

As of: Oct 1, 2026 · 2:14 PM EDT

Institutions by Trading Activity

149 Institutions

Increased 96 64.4%

Unchanged 15 10.1%

Reduced 38 25.5%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

106.79%

▲+5.71 pp QoQ

Shares Held by Institutions

48.21Mn

of 45.15Mn outstanding

▲+6.32% QoQ

Shares Outstanding

45.15Mn

-3.07Mn held outside 13F filers

Institutional Investors

149

filed 13F for Jun 2026

▲+28 vs prior quarter

Net Shares Added (QoQ)

+2.86Mn

accumulated since last quarter

Value of Holdings

$253.61Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Quarter ending 30 Jun, 2026

Sionna Therapeutics, Inc. (NASDAQ:SION) has 149 institutional investors with active 13F positions as of June 2026.

These investors held 106.8% of outstanding shares in June 2026, up from 101.1% in March 2026.
Their total shares held in SION increased 6.32% from the prior quarter, while the number of investors in Sionna Therapeutics increased 136.51% year over year.
During the quarter, 96 of these 149 funds increased positions in SION, 38 reduced exposure, and 15 held steady.
Combined, these investors held 48.21Mn shares in SION for June 2026, up by 2.86Mn shares quarter on quarter, and up 4.94Mn shares year over year.
RA CAPITAL MANAGEMENT, L.P. holds the largest position in SION at 9.91Mn shares as of June 30, 2026, or 21.94% of shares outstanding.
Top purchasers of SION stock for the quarter ending June 2026 included ADAGE CAPITAL PARTNERS GP, L.L.C. (1.45Mn), Casdin Capital, LLC (400.0K), Siren, L.L.C. (310.52K), DRIEHAUS CAPITAL MANAGEMENT LLC (308.81K), State Street Corp (265.31K).
The biggest sellers of Sionna Therapeutics for the quarter ending June 2026 included ORBIMED ADVISORS LLC (974.82K), DEERFIELD MANAGEMENT COMPANY, L.P. (289.67K), Aberdeen Group plc (280.04K), JENNISON ASSOCIATES LLC (279.09K), PRICE T ROWE ASSOCIATES INC /MD/ (278.36K).
Per Business Quant data, the top 10 holders of Sionna Therapeutics for the quarter ending June 2026 are RA CAPITAL MANAGEMENT, L.P. (9.91Mn), TPG GP A, LLC (6.49Mn), VIKING GLOBAL INVESTORS LP (3.2Mn), Atlas Venture Life Science Advisors, LLC (3.0Mn), ORBIMED ADVISORS LLC (2.56Mn), Enavate Sciences GP, LLC (2.48Mn), ADAGE CAPITAL PARTNERS GP, L.L.C. (1.6Mn), Jpmorgan Chase & Co (1.49Mn), BlackRock, Inc. (1.47Mn), JENNISON ASSOCIATES LLC (1.17Mn).

Form 13F Holdings

149 Institutional Holders

Report period 30 Jun, 2026

Total shares held 48.21Mn

Of outstanding 106.79%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	RA CAPITAL MANAGEMENT, L.P.	0001346824	9,905,045	21.94%	0	0.00%	$435.72Mn
2	TPG GP A, LLC	0001903793	6,494,962	14.39%	0	0.00%	$285.71Mn
3	VIKING GLOBAL INVESTORS LP	0001103804	3,195,181	7.08%	0	0.00%	$140.56Mn
4	Atlas Venture Life Science Advisors, LLC	0001917529	2,995,602	6.63%	0	0.00%	$131.78Mn
5	ORBIMED ADVISORS LLC	0001055951	2,555,877	5.66%	▼974,825	-27.61%	$112.43Mn
6	Enavate Sciences GP, LLC	0001953107	2,478,030	5.49%	0	0.00%	$109.01Mn
7	ADAGE CAPITAL PARTNERS GP, L.L.C.	0001165408	1,600,000	3.54%	▲1,450,000	+966.67%	$70.38Mn
8	Jpmorgan Chase & Co	0000019617	1,490,508	3.30%	▲25,494	+1.74%	$64.09Mn
9	BlackRock, Inc.	0002012383	1,474,769	3.27%	▲178,902	+13.81%	$64.88Mn
10	JENNISON ASSOCIATES LLC	0000053417	1,172,133	2.60%	▼279,087	-19.23%	$51.56Mn
11	CITADEL ADVISORS LLC	0001423053	1,147,636	2.54%	▼19,295	-1.65%	$50.48Mn
12	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	1,132,001	2.51%	▲102,504	+9.96%	$49.80Mn
13	State Street Corp	0000093751	1,021,534	2.26%	▲265,307	+35.08%	$44.94Mn
14	PERCEPTIVE ADVISORS LLC	0001224962	905,000	2.00%	▲246,561	+37.45%	$39.81Mn
15	DEERFIELD MANAGEMENT COMPANY, L.P.	0001009258	680,916	1.51%	▼289,674	-29.85%	$29.95Mn
16	Siren, L.L.C.	0002005245	610,515	1.35%	▲310,515	+103.51%	$26.86Mn
17	PRICE T ROWE ASSOCIATES INC /MD/	0000080255	478,016	1.06%	▼278,360	-36.80%	$21.03K
18	EVENTIDE ASSET MANAGEMENT, LLC	0001442891	474,981	1.05%	▼170,549	-26.42%	$20.89Mn
19	GEODE CAPITAL MANAGEMENT, LLC	0001214717	457,145	1.01%	▲67,273	+17.26%	$20.11Mn
20	BAKER BROS. ADVISORS LP	0001263508	400,000	0.89%	0	0.00%	$17.60Mn

Showing 1 to 20 of 149 holders