Sionna Therapeutics, Inc.: which funds bought and sold

Institutions that bought and sold Sionna Therapeutics shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.

Between March 31, 2026 and June 30, 2026, 89 institutions that filed 13F reports for both quarters added to or opened positions in Sionna Therapeutics, and 48 cut or closed them. Together they added a net 2.6M shares, +5.6% on what they held at the start of the quarter. Active managers and hedge funds on our list were net buyers of 2.3M shares (+11.6%); index fund managers were net buyers of 751K shares (+18.8%). 34 opened a new position and 8 sold out entirely.

Bought, Q2 2026 89 institutions, 34 of them new holders Sold, Q2 2026 48 institutions, 8 of them sold out

Net change, all compared +2.6M shares (+5.6%)

Net change, active managers +2.3M shares (+11.6%), 21 bought, 13 sold

Buyers versus sellers

institutions compared, 152

89 bought 15 48 sold

Active managers and hedge funds 21 bought · 13 sold · +2.3M

Index fund managers 9 bought · 1 sold · +751K

Other institutions 59 bought · 34 sold · −509K

Biggest buyers

by change in shares held

Biggest buyers
Institution	Change in shares	Shares June 30, 2026	Value
Adage Capital Partners Gp, L.L.C. Hedge fund	+1.4M +966.7%	1.6M	$70.4M
Casdin Capital, LLC Hedge fund	+400K New position	400K	$17.6M
Siren, L.L.C.	+311K +103.5%	611K	$26.9M
Driehaus Capital Management LLC Active manager	+309K +403.0%	385K	$17M
State Street Corp Index funds	+265K +35.1%	1.0M	$44.9M
Perceptive Advisors LLC Hedge fund	+247K +37.4%	905K	$39.8M
FMR LLC Active manager	+197K +241.9%	278K	$12.2M
Artisan Partners Limited Partnership Active manager	+189K New position	189K	$8.3M
Longaeva Partners L.P.	+184K +1446.9%	196K	$8.6M
Blackrock, Inc. Index funds	+179K +13.8%	1.5M	$64.9M
Sofinnova Investments, Inc.	+144K New position	144K	$6.4M
Millennium Management LLC Hedge fund	+136K +96.8%	277K	$12.2M
Goldman Sachs Group Inc	+126K +47.7%	389K	$17.1M
Franklin Resources Inc Active manager	+115K +65.3%	290K	$12.8M
First Turn Management, LLC	+110K New position	110K	$4.9M
Vanguard Capital Management LLC Index funds	+103K +10.0%	1.1M	$49.8M
D. E. Shaw & Co., Inc. Hedge fund	+102K New position	102K	$4.5M
Qube Research & Technologies Ltd Hedge fund	+98K +232.2%	140K	$6.2M
Citigroup Inc	+92K +510.1%	110K	$4.8M
Walleye Capital LLC Hedge fund	+82K +544.8%	97K	$4.3M

Biggest buyers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Adage Capital Partners Gp, L.L.C. Hedge fund	+1.4M +966.7%	1.6M	$70.4M
Casdin Capital, LLC Hedge fund	+400K New position	400K	$17.6M
Driehaus Capital Management LLC Active manager	+309K +403.0%	385K	$17M
Perceptive Advisors LLC Hedge fund	+247K +37.4%	905K	$39.8M
FMR LLC Active manager	+197K +241.9%	278K	$12.2M
Artisan Partners Limited Partnership Active manager	+189K New position	189K	$8.3M
Millennium Management LLC Hedge fund	+136K +96.8%	277K	$12.2M
Franklin Resources Inc Active manager	+115K +65.3%	290K	$12.8M
D. E. Shaw & Co., Inc. Hedge fund	+102K New position	102K	$4.5M
Qube Research & Technologies Ltd Hedge fund	+98K +232.2%	140K	$6.2M

Biggest sellers

by change in shares held

Biggest sellers
Institution	Change in shares	Shares June 30, 2026	Value
Orbimed Advisors LLC	−975K −27.6%	2.6M	$112M
Deerfield Management Company, L.P. Hedge fund	−290K −29.8%	681K	$30M
Aberdeen Group PLC	−280K −49.6%	284K	$12.5M
Jennison Associates LLC Active manager	−279K −19.2%	1.2M	$51.6M
Price T Rowe Associates Inc Active manager	−278K −36.8%	478K	$21M
Eventide Asset Management, LLC	−171K −26.4%	475K	$20.9M
Sio Capital Management, LLC	−167K −56.6%	128K	$5.6M
Soleus Capital Management, L.P. Hedge fund	−116K −39.5%	178K	$7.8M
Point72 Asset Management, L.P. Hedge fund	−87K −63.9%	49K	$2.2M
Superstring Capital Management LP	−78K −55.2%	63K	$2.8M
Ensign Peak Advisors, Inc	−71K −27.8%	185K	$8.1M
TD Asset Management Inc	−36K −42.9%	47K	$2.1M
UBS Group AG	−31K −21.3%	116K	$5.1M
Manufacturers Life Insurance Company, The	−29K −45.0%	35K	$1.6M
Polen Capital Management LLC Active manager	−27K Sold out	0	—
Citadel Advisors LLC Hedge fund	−19K −1.7%	1.1M	$50.5M
Stempoint Capital LP	−14K −18.7%	59K	$2.6M
Barclays PLC	−12K −64.7%	6,495	$285,715
Squarepoint Ops LLC Hedge fund	−9,802 −64.4%	5,415	$238,206
BNP Paribas Financial Markets	−8,767 −21.6%	32K	$1.4M

Biggest sellers, active managers and hedge funds
Institution	Change in shares	Shares June 30, 2026	Value
Deerfield Management Company, L.P. Hedge fund	−290K −29.8%	681K	$30M
Jennison Associates LLC Active manager	−279K −19.2%	1.2M	$51.6M
Price T Rowe Associates Inc Active manager	−278K −36.8%	478K	$21M
Soleus Capital Management, L.P. Hedge fund	−116K −39.5%	178K	$7.8M
Point72 Asset Management, L.P. Hedge fund	−87K −63.9%	49K	$2.2M
Polen Capital Management LLC Active manager	−27K Sold out	0	—
Citadel Advisors LLC Hedge fund	−19K −1.7%	1.1M	$50.5M
Squarepoint Ops LLC Hedge fund	−9,802 −64.4%	5,415	$238,206
Wellington Management Group LLP Active manager	−8,714 −18.9%	37K	$1.6M
Exoduspoint Capital Management, LP Hedge fund	−7,190 Sold out	0	—

New positions

largest by value

Institution	Shares	Value June 30, 2026
Casdin Capital, LLCHedge fund	400K	$17.6M
Artisan Partners Limited PartnershipActive manager	189K	$8.3M
Sofinnova Investments, Inc.	144K	$6.4M
First Turn Management, LLC	110K	$4.9M
D. E. Shaw & Co., Inc.Hedge fund	102K	$4.5M
Mutual Of America Capital Management LLC	36K	$1.6M
Swiss National Bank	27K	$1.2M
Quadrature Capital LtdHedge fund	26K	$1.1M
Trexquant Investment LPHedge fund	24K	$1M
Tudor Investment Corp Et AlHedge fund	23K	$993,074

Sold out

largest by value

Institution	Shares	Value March 31, 2026
Polen Capital Management LLCActive manager	27K	$1.1M
Susquehanna International Group, LLP	7,310	$293,058
Exoduspoint Capital Management, LPHedge fund	7,190	$288,247
Hudson Bay Capital Management LPHedge fund	6,180	$247,756
Two Sigma Investments, LPHedge fund	5,500	$220,495
Signaturefd, LLC	24	$962
Root Financial Partners, LLC	10	$401
Mai Capital Management	2	$81

Who holds the shares

13F holdings at June 30, 2026

Institutions reporting: 145
Ten largest holders: 69.3%
Index fund managers: 9.9%
Active managers and hedge funds: 46.3%

Buying and selling by type of institution, March 31, 2026 to June 30, 2026
Type	Bought	Sold	New	Sold out	Net change in shares	Net %
Active managers and hedge funds	21	13	9	4	+2.3M	+11.6%
Index fund managers	9	1	0	0	+751K	+18.8%
Other institutions	59	34	25	4	−509K	−2.4%

Active managers and hedge funds: a list we maintain of about 400 well-known stock-picking firms and hedge funds, matched by SEC registration number (CIK) and checked against the filer names each quarter. Index fund managers: the large index houses, such as BlackRock, Vanguard, State Street, Geode and Northern Trust. Every other filer (banks, brokers, wealth managers, pension funds, insurers and firms not on the list) counts as another institution. A firm that files under several SEC registrations appears once for each.

What these filings can and cannot tell you

Form 13F lists the long positions in US-listed shares held by investment managers with more than $100 million in such holdings. Managers file it up to 45 days after each quarter ends, so this page shows what funds held at the end of each quarter, not what they are doing now: a position may have changed since. Short positions, most derivatives and smaller managers are not included, and a cut can mean a fund lost clients or rebalanced rather than a view on Sionna Therapeutics.

Only managers that filed a holdings report for both quarters are compared (152 here). 4 other holders are left out: first-time or late filers, firms that changed their SEC registration, and filings that withheld positions under confidential treatment, any of which would otherwise look like a new position or a sale. Figures are as reported by each manager in the SEC's quarterly 13F data sets; option positions are excluded.

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