Sionna Therapeutics Ownership | Who Owns Sionna Therapeutics?

Sionna Therapeutics Ownership Summary

Sionna Therapeutics is owned by 98.48% institutional investors, 7.20% insiders. Ra capital management is the largest institutional shareholder, holding 23.68% of SION shares.

SION Ownership Benchmark

Type	Name	% Inst	% Insiders	% Retail
Stock	Sionna Therapeutics	98.48%	7.20%	-5.69%
Sector	Healthcare Stocks	486.50%	11.08%	-397.59%
Industry	Biotech Stocks	304.14%	11.08%	-215.23%

Institutional Shareholders

Top Institutional Shareholders by Total Shares

Holder	Shares	% Holding	Value
Ra capital management	10.45M	23.68%	$181.23M
Orbimed advisors	3.70M	8.40%	$64.28M
Atlas venture life science advisors	3.69M	8.37%	$64.09M
Viking global investors lp	3.20M	7.24%	$55.44M
Perceptive advisors	1.22M	2.76%	$21.10M
Braidwell lp	1.08M	2.45%	$18.77M
Deerfield management company, l.p. (series c)	970.59K	2.20%	$16.84M
Abrdn	950.55K	2.15%	$16.49M
Jennison associates	752.80K	1.71%	$13.06M
Blackrock funding, inc. /de	637.10K	1.44%	$11.05M

Top Institutional Shareholders by % of Total Assets

Holder	Shares	% Assets	Value
Atlas venture life science advisors	3.69M	9.68%	$64.09M
Ra capital management	10.45M	3.05%	$181.23M
Orbimed advisors	3.70M	1.61%	$64.28M
Perceptive advisors	1.22M	0.78%	$21.10M
Braidwell lp	1.08M	0.64%	$18.77M
Silverarc capital management	186.01K	0.60%	$3.23M
Soleus capital management	376.00K	0.43%	$6.52M
Deerfield management company, l.p. (series c)	970.59K	0.31%	$16.84M
Siren	325.00K	0.29%	$5.64M
Viking global investors lp	3.20M	0.16%	$55.44M

Top Buyers

Holder	Shares	% Assets	Change
Braidwell lp	1.08M	0.64%	1.08M
Blackrock funding, inc. /de	637.10K	0.00%	438.71K
Viking global investors lp	3.20M	0.16%	242.43K
Deerfield management company, l.p. (series c)	970.59K	0.31%	223.59K
Abrdn	950.55K	0.03%	204.58K

Top Sellers

Holder	Shares	% Assets	Change
Driehaus capital management	83.85K	0.01%	-245.04K
Zimmer partners, lp	-	-	-237.50K
Centerbook partners lp	-	-	-114.28K
Jennison associates	752.80K	0.01%	-107.13K
Stempoint capital lp	-	-	-60.00K

New Positions

Holder	Shares	% Assets	Change	Value
Braidwell lp	1.08M	0.64%	1.08M	$18.77M
Polen capital management	16.98K	0.00%	16.98K	$294.52K
Options solutions	16.98K	0.09%	16.98K	$294.52K
Virtus investment advisers	5.54K	0.03%	5.54K	$96.03K
Sterling capital management	30.00	-	30.00	$521.00

Sold Out

Holder	Change
Two sigma investments, lp	-11.71K
Marshall wace, llp	-12.19K
Balyasny asset management	-13.06K
Squarepoint ops	-33.96K
Stempoint capital lp	-60.00K

Institutional Ownership Trends

Date	Holdings	Change %	Shares	Change %	Ownership	Change %	Increased Position	Change %	Decreased Position	Change %
Jun 30, 2025	65	38.30%	43,448,395	4.72%	98	0.40%	44	-6.38%	10	-
Mar 31, 2025	47	-	41,491,947	-	156	-	47	-	-	-

Recent Insider Transactions

Date	Name	Role	Activity	Value
Aug 20, 2025	Cloonan Michael	President & CEO	Sell	$568.75K
Aug 19, 2025	Ridloff Elena	CFO & Head of Corp. Dev.	Sell	$727.26K
Aug 20, 2025	Ridloff Elena	CFO & Head of Corp. Dev.	Sell	$397.07K
Jun 27, 2025	TPG GP A, LLC	-	Buy	$950.40K

Insider Transactions Trends

Date	Buy	Sell
2025 Q3	-	3
2025 Q2	1	-

SION Ownership FAQ

Who Owns Sionna Therapeutics?

Sionna Therapeutics shareholders are primarily institutional investors at 98.48%, followed by 7.20% insiders and -5.68% retail investors. The average institutional ownership in Sionna Therapeutics's industry, Biotech Stocks , is 304.14%, which Sionna Therapeutics falls below.

Who owns the most shares of Sionna Therapeutics?

Sionna Therapeutics’s largest shareholders are Ra capital management (10.45M shares, 23.68%), Orbimed advisors (3.7M shares, 8.40%), and Atlas venture life science advisors (3.69M shares, 8.37%). Together, they hold 40.45% of Sionna Therapeutics’s total shares outstanding.

Does Blackrock own Sionna Therapeutics?

BlackRock is not among the top 10 institutional shareholders of Sionna Therapeutics.

Who is Sionna Therapeutics’s biggest shareholder by percentage of total assets invested?

Atlas venture life science advisors is Sionna Therapeutics’s biggest shareholder by percentage of total assets invested, with 9.68% of its assets in 3.69M Sionna Therapeutics shares, valued at 64.09M$.

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