SION · Sionna Therapeutics, Inc. · Holdings

$7.85 +0.23 (+3.02%) At close · Sep 11

Russell 2000 member Rebalance outlook locked

Market Cap

$354.92M

45.21M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Use institutional holdings through the 13F API or MCP →

Quarter:

Holders: 150

Total Value: $2,124,809,280

Total Shares: 48,302,112

Showing 1–100 of 154 holdings by value · page 1 of 2

Institutional Ownership Trend

6 quarters

Superinvestors Holding SION

All superinvestors →

Andreas Halvorsen $140,556,012

Holder Concentration

Across 150 13F filers · Δ vs Mar 31, 2026

Top Holder

20.5%

−1.3 pts

Top 5

52.1%

−5.5 pts

Top 10

69.1%

−5.8 pts

HHI

806

Broadly held−119

Quarterly Activity

vs Mar 31, 2026

New

Increased

Decreased

Sold Out

Unchanged

Holder count: +28

Institutional value: +16.7%

Shares held: +6.4%

Top Buyers

vs Mar 31, 2026

Institution	Added	Now Holds
Large ADAGE CAPITAL PARTNERS GP, L.L.C.	+1,450,000	1,600,000
Mid Siren, L.L.C.	+310,515	610,515
Large Driehaus Capital Management LLC	+308,814	385,447
Mega STATE STREET CORP	+265,307	1,021,534
Mid PERCEPTIVE ADVISORS LLC	+246,561	905,000

Top Sellers

vs Mar 31, 2026

Institution	Sold	Now Holds
Mid ORBIMED ADVISORS LLC	−974,825	2,555,877
Mid DEERFIELD MANAGEMENT COMPANY, L.P.	−289,674	680,916
Large Aberdeen Group plc	−280,037	284,138
Mega JENNISON ASSOCIATES LLC	−279,087	1,172,133
Mega PRICE T ROWE ASSOCIATES INC /MD/	−278,360	478,016

Top New Positions

vs Mar 31, 2026

Institution	Acquired	Value (USD)
Mid Casdin Capital, LLC	400,000	$17,596,000
Large Artisan Partners Limited Partnership	189,498	$8,336,017
Mid Sofinnova Investments, Inc.	144,432	$6,353,563
Small First Turn Management, LLC	110,493	$4,860,587
Small Ikarian Capital, LLC	107,500	$4,728,925

Top Sold-Out Positions

vs Mar 31, 2026

Institution	Previously Held	Last Value (USD)
Large POLEN CAPITAL MANAGEMENT LLC	26,775	$1,073,409
Large ExodusPoint Capital Management, LP	7,190	$288,247
Large Hudson Bay Capital Management LP	6,180	$247,756
Mega TWO SIGMA INVESTMENTS, LP	5,500	$220,495
Small Cygnus Capital Advisors, LLC	3,800	$152,342

Filter: New 37 Increased 59 Reduced 39 Sold out 9 Unchanged 15

Showing 100 of 154

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

RA CAPITAL MANAGEMENT, L.P.

$435,722,929

20.51%

9,905,045

TPG GP A, LLC

$285,713,378

13.45%

6,494,962

VIKING GLOBAL INVESTORS LP

$140,556,012

6.61%

3,195,181

Atlas Venture Life Science Advisors, LLC

$131,776,531

6.20%

2,995,602

ORBIMED ADVISORS LLC

$112,433,029

5.29%

2,555,877

ENAVATE SCIENCES GP, LLC

$109,008,539

5.13%

2,478,030

ADAGE CAPITAL PARTNERS GP, L.L.C.

$70,384,000

3.31%

1,600,000

JPMORGAN CHASE & CO

$65,567,443

3.09%

1,490,508

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
JPMorgan Chase Bank, N.A.	26,704	$1,174,708	1.8%	Defined
J.P. Morgan Investment Management Inc.	838,217	$36,873,165	56.2%	Defined
J.P. Morgan Securities LLC	1	$43	0.0%	Defined
J.P. Morgan Securities plc	3,434	$151,061	0.2%	Defined
JPMorgan Asset Management (UK) Ltd	622,152	$27,368,466	41.7%	Defined

BlackRock, Inc.

$64,875,084

3.05%

1,474,769

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
BLACKROCK FINANCIAL MANAGEMENT INC/DE	13,100	$576,269	0.9%	Sole
BlackRock Asset Management Canada Ltd	189	$8,314	0.0%	Sole
BlackRock Investment Management, LLC	50,724	$2,231,348	3.4%	Sole
BLACKROCK ADVISORS LLC	41,711	$1,834,866	2.8%	Sole
BlackRock Fund Advisors	880,122	$38,716,566	59.7%	Sole
BlackRock Institutional Trust Company, N.A.	437,016	$19,224,333	29.6%	Sole
BlackRock Asset Management Ireland Ltd	44,493	$1,957,247	3.0%	Sole
Aperio Group, LLC	7,414	$326,141	0.5%	Sole

JENNISON ASSOCIATES LLC

$51,562,130

2.43%

1,172,133

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Prudential Financial Inc	1,172,133	$51,562,130	100.0%	Defined

CITADEL ADVISORS LLC

$50,484,507

2.38%

1,147,636

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Citadel Securities GP LLC	7,762	$341,450	0.7%	Defined
Held directly	1,139,874	$50,143,057	99.3%	Defined

VANGUARD CAPITAL MANAGEMENT LLC

$49,796,723

2.34%

1,132,001

STATE STREET CORP

$44,937,280

2.11%

1,021,534

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
STATE STREET GLOBAL ADVISORS EUROPE LIMITED joint	1,021,534	$44,937,280	100.0%	Defined

PERCEPTIVE ADVISORS LLC

$39,810,950

1.87%

905,000

DEERFIELD MANAGEMENT COMPANY, L.P.

$29,953,494

1.41%

680,916

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Deerfield UGP, LLC	680,916	$29,953,494	100.0%	Defined

Siren, L.L.C.

$26,856,554

1.26%

610,515

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Invus Group, LLC	610,515	$26,856,554	100.0%	Defined

PRICE T ROWE ASSOCIATES INC /MD/

$21,027,923

0.99%

478,016

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
T. Rowe Price International Ltd	19,585	$861,544	4.1%	Defined
Held directly	458,431	$20,166,379	95.9%	Sole

EVENTIDE ASSET MANAGEMENT, LLC

$20,894,414

0.98%

474,981

GEODE CAPITAL MANAGEMENT, LLC

$20,109,808

0.95%

457,145

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
GEODE CAPITAL MANAGEMENT TRUST COMPANY, LLC	58,765	$2,585,072	12.9%	Defined
Held directly	398,380	$17,524,736	87.1%	Defined

Casdin Capital, LLC

$17,596,000

0.83%

400,000

BAKER BROS. ADVISORS LP

$17,596,000

0.83%

400,000

GOLDMAN SACHS GROUP INC

$17,103,751

0.80%

388,810

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
GOLDMAN SACHS & CO. LLC	365,993	$16,100,032	94.1%	Defined
GOLDMAN SACHS ASSET MANAGEMENT, L.P.	22,817	$1,003,719	5.9%	Defined

Driehaus Capital Management LLC

$16,955,813

0.80%

385,447

FRANKLIN RESOURCES INC

$12,762,070

0.60%

290,113

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
FRANKLIN ADVISERS INC	290,113	$12,762,070	100.0%	Defined

Aberdeen Group plc

$12,499,230

0.59%

284,138

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
abrdn Inc.	284,138	$12,499,230	100.0%	Defined

FMR LLC

$12,242,065

0.58%

278,292

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Fidelity Management & Research Co LLC	278,292	$12,242,065	100.0%	Defined

MILLENNIUM MANAGEMENT LLC

$12,173,484

0.57%

276,733

Candriam S.C.A.

$10,258,819

0.48%

233,208

VANGUARD PORTFOLIO MANAGEMENT LLC

$9,807,526

0.46%

222,949

Kalehua Capital Management LLC

$8,669,197

0.41%

197,072

Longaeva Partners L.P.

$8,637,524

0.41%

196,352

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Balyasny Asset Management L.P.	196,352	$8,637,524	100.0%	Other

Artisan Partners Limited Partnership

$8,336,017

0.39%

189,498

Ensign Peak Advisors, Inc

$8,117,562

0.38%

184,532

Soleus Capital Management, L.P.

$7,816,451

0.37%

177,687

NORTHERN TRUST CORP

$6,795,398

0.32%

154,476

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
NORTHERN TRUST CO joint	151,580	$6,668,003	98.1%	Defined
DWS INVESTMENT MANAGEMENT AMERICAS, INC joint	2,896	$127,395	1.9%	Other

MORGAN STANLEY

$6,644,554

0.31%

151,047

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
MORGAN STANLEY & CO INTERNATIONAL PLC	308	$13,548	0.2%	Defined
MORGAN STANLEY & CO. LLC	8,868	$390,103	5.9%	Defined
MORGAN STANLEY CAPITAL SERVICES, LLC	113,024	$4,971,925	74.8%	Defined
MORGAN STANLEY SMITH BARNEY LLC	2,400	$105,576	1.6%	Defined
PARAMETRIC PORTFOLIO ASSOCIATES LLC	26,447	$1,163,402	17.5%	Defined

Sofinnova Investments, Inc.

$6,353,563

0.30%

144,432

Qube Research & Technologies Ltd

$6,172,192

0.29%

140,309

Alyeska Investment Group, L.P.

$5,992,405

0.28%

136,222

GordonMD Global Investments LP

$5,982,640

0.28%

136,000

CHARLES SCHWAB INVESTMENT MANAGEMENT INC

$5,707,834

0.27%

129,753

Sio Capital Management, LLC

$5,622,273

0.26%

127,808

Ishara Investments LP

$5,410,770

0.25%

123,000

VANGUARD FIDUCIARY TRUST CO

$5,342,233

0.25%

121,442

Artia Global Partners LP

$5,267,406

0.25%

119,741

UBS Group AG

$5,111,901

0.24%

116,206

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS AG	116,206	$5,111,901	100.0%	Defined

First Turn Management, LLC

$4,860,587

0.23%

110,493

CITIGROUP INC

$4,846,070

0.23%

110,163

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Citigroup Financial Products Inc. joint	110,163	$4,846,070	100.0%	Defined

Ikarian Capital, LLC

$4,728,925

0.22%

107,500

D. E. Shaw & Co., Inc.

$4,471,318

0.21%

101,644

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
D. E. SHAW & CO, L.P.	90,902	$3,998,778	89.4%	Defined
D. E. Shaw Investment Management, L.L.C. joint	10,742	$472,540	10.6%	Defined

Rock Springs Capital Management LP

$4,373,881

0.21%

99,429

Walleye Capital LLC

$4,282,294

0.20%

97,347

Rhenman & Partners Asset Management AB

$4,271,429

0.20%

97,100

BANK OF AMERICA CORP /DE/

$3,911,062

0.18%

88,908

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
BANK OF AMERICA NA	74,395	$3,272,636	83.7%	Defined
BOFA SECURITIES, INC.	14,513	$638,426	16.3%	Defined

AMERIPRISE FINANCIAL INC

$3,617,385

0.17%

82,232

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Columbia Management Investment Advisers, LLC	82,232	$3,617,385	100.0%	Defined

Integral Health Asset Management, LLC

$3,299,250

0.16%

75,000

SUPERSTRING CAPITAL MANAGEMENT LP

$2,778,232

0.13%

63,156

STEMPOINT CAPITAL LP

$2,614,149

0.12%

59,426

DEUTSCHE BANK AG\

$2,346,998

0.11%

53,353

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
DWS Investment GmbH	35,000	$1,539,650	65.6%	Defined
DWS INVESTMENT MANAGEMENT AMERICAS, INC	358	$15,748	0.7%	Defined
DWS Investments UK Ltd	17,995	$791,600	33.7%	Defined

SEVEN GRAND MANAGERS, LLC

$2,199,500

0.10%

50,000

Point72 Asset Management, L.P.

$2,169,938

0.10%

49,328

TD Asset Management Inc

$2,084,950

0.10%

47,396

ALPS ADVISORS INC

$2,002,644

0.09%

45,525

SILVERARC CAPITAL MANAGEMENT, LLC

$1,868,607

0.09%

42,478

Russell Investments Group, Ltd.

$1,858,928

0.09%

42,258

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Russell Investment Management, LLC	20,350	$895,196	48.2%	Defined
Russell Investments Capital, LLC	8,982	$395,118	21.3%	Defined
Russell Investments France SAS	4,033	$177,411	9.5%	Defined
Russell Investments Trust Company	8,893	$391,203	21.0%	Defined

Bank of New York Mellon Corp

$1,829,365

0.09%

41,586

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Mellon Investments Corporation	10,832	$476,499	26.0%	Defined
The Bank of New York Mellon	30,743	$1,352,384	73.9%	Defined
BNY Mellon, NA joint	10	$439	0.0%	Defined
Held directly	1	$43	0.0%	Defined

Nuveen, LLC

$1,814,982

0.09%

41,259

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Nuveen Asset Management, LLC joint	3,712	$163,290	9.0%	Defined
TEACHERS ADVISORS, LLC joint	37,547	$1,651,692	91.0%	Defined

XTX Topco Ltd

$1,675,843

0.08%

38,096

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
XTX EXECUTION SERVICES LLC joint	38,096	$1,675,843	100.0%	Defined

WELLINGTON MANAGEMENT GROUP LLP

$1,643,685

0.08%

37,365

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Wellington Management Company LLP	11,722	$515,650	31.4%	Defined
Wellington Trust Company, NA joint	23,472	$1,032,533	62.8%	Defined
Wellington Management Australia Pty Ltd	2,171	$95,502	5.8%	Defined

MUTUAL OF AMERICA CAPITAL MANAGEMENT LLC

$1,582,232

0.07%

35,968

MANUFACTURERS LIFE INSURANCE COMPANY, THE

$1,558,125

0.07%

35,420

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
MANULIFE FINANCIAL CORP joint	35,420	$1,558,125	100.0%	Defined

BOOTHBAY FUND MANAGEMENT, LLC

$1,429,675

0.07%

32,500

BNP PARIBAS ARBITRAGE, SA

$1,399,013

0.07%

31,803

MILLENNIUM MANAGEMENT LLC

$1,258,114

0.06%

28,600

Swiss National Bank

$1,187,730

0.06%

27,000

Quadrature Capital Ltd

$1,144,751

0.05%

26,023

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Quadrature US Inc.	26,023	$1,144,751	100.0%	Other

ALLIANCEBERNSTEIN L.P.

$1,119,545

0.05%

25,450

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Equitable Holdings, Inc.	25,450	$1,119,545	100.0%	Defined

Trexquant Investment LP

$1,047,401

0.05%

23,810

NEW YORK STATE COMMON RETIREMENT FUND

$1,037,548

0.05%

23,586

TUDOR INVESTMENT CORP ET AL

$993,074

0.05%

22,575

RHUMBLINE ADVISERS

$981,372

0.05%

22,309

MILLENNIUM MANAGEMENT LLC

$879,800

0.04%

20,000

Maven Securities LTD

$879,800

0.04%

20,000

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Maven Investment Partners US Ltd	20,000	$879,800	100.0%	Defined

LOS ANGELES CAPITAL MANAGEMENT LLC

$820,193

0.04%

18,645

Susquehanna Portfolio Strategies, LLC

$793,315

0.04%

18,034

Rafferty Asset Management, LLC

$791,995

0.04%

18,004

Shay Capital LLC

$791,820

0.04%

18,000

WELLS FARGO & COMPANY/MN

$739,955

0.03%

16,821

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
WELLS FARGO BANK N A	16,456	$723,899	97.8%	Defined
Wells Fargo Securities, LLC	365	$16,056	2.2%	Defined

Engineers Gate Manager LP

$686,375

0.03%

15,603

CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM

$653,339

0.03%

14,852

KENNEDY CAPITAL MANAGEMENT LLC

$555,197

0.03%

12,621

MARSHALL WACE, LLP

$554,230

0.03%

12,599

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Marshall Wace North America L.P. joint	12,599	$554,230	100.0%	Other

Invesco Ltd.

$546,266

0.03%

12,418

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Invesco Advisers, Inc. joint	2,811	$123,655	22.6%	Defined
Invesco Trust Co joint	7,318	$321,918	58.9%	Defined
Invesco Capital Management LLC	2,289	$100,693	18.4%	Defined

MetLife Investment Management, LLC

$482,658

0.02%

10,972

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
METLIFE INC	10,972	$482,658	100.0%	Defined

UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC

$467,260

0.02%

10,622

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
UBS Group AG	116	$5,102	1.1%	Defined
UBS Asset Management Switzerland AG	10,506	$462,158	98.9%	Sole

MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.

$465,502

0.02%

10,582

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Global X Management CO LLC joint	8,491	$373,519	80.2%	Defined
Global X Management (AUS) Ltd joint	2,091	$91,983	19.8%	Defined

Jump Financial, LLC

$460,707

0.02%

10,473

This filing is a combination report: the position is filed across the managers below.

Manager	Shares	Value (USD)	% of position	Discretion
Leap GP LLC joint	10,473	$460,707	100.0%	Defined

VANGUARD ASSET MANAGEMENT, Ltd

$419,444

0.02%

9,535

PROFUND ADVISORS LLC

$402,068

0.02%

9,140

Virtus Investment Advisers, LLC

$400,704

0.02%

9,109

Key facts CIK 2036042 CUSIP 829401108 13F (30d) 94 filings 94 filers Visit website Investor relations