AMLX · Amylyx Pharmaceuticals, Inc.

$34.10 +0.14 (+0.41%) At close · Sep 4

Russell 2000 member Rebalance outlook locked

Market Cap

$3.80B

111.42M

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: 208

Total Value: $2,077,650,284

Total Shares: 115,682,127

Showing 1–100 of 221 holdings by value · page 1 of 3

Institutional Ownership Trend

18 quarters

Holder Concentration

Across 208 13F filers · Δ vs Mar 31, 2026

Top Holder

14.5%

−0.0 pts

Top 5

39.6%

−0.2 pts

Top 10

57.1%

−0.4 pts

HHI

486

Broadly held−6

Quarterly Activity

vs Mar 31, 2026

New

Increased

Decreased

Sold Out

Unchanged

Holder count: +35

Institutional value: +30.3%

Shares held: +0.9%

Top Buyers

vs Mar 31, 2026

Institution	Added	Now Holds
Mega JPMORGAN CHASE & CO	+1,703,987	1,863,650
Mega MORGAN STANLEY	+955,261	3,130,808
Mega FRANKLIN RESOURCES INC	+688,656	2,950,225
Mega TWO SIGMA INVESTMENTS, LP	+431,490	593,435
Mega JANE STREET GROUP, LLC	+351,565	377,165

Top Sellers

vs Mar 31, 2026

Institution	Sold	Now Holds
Large ADAGE CAPITAL PARTNERS GP, L.L.C.	−1,660,764	1,900,000
Small Almitas Capital LLC	−1,147,716	974,881
Small GREAT POINT PARTNERS LLC	−1,050,000	700,000
Mega BARCLAYS PLC	−915,596	56,258
Mega DEUTSCHE BANK AG\	−709,848	557,937

Top New Positions

vs Mar 31, 2026

Institution	Acquired	Value (USD)
Mega Jupiter Topco LLC	5,236,102	$94,040,391
Large Alyeska Investment Group, L.P.	1,053,015	$18,912,149
Large Aberdeen Group plc	737,670	$13,248,553
Mid Nearwater Capital Markets, Ltd	425,000	$7,633,000
Large Trexquant Investment LP	349,439	$6,275,924

Top Sold-Out Positions

vs Mar 31, 2026

Institution	Previously Held	Last Value (USD)
Mega JANUS HENDERSON GROUP PLC	4,986,073	$69,306,414
Large Squarepoint Ops LLC	114,877	$1,596,790
Mid Informed Momentum Co LLC	53,256	$740,258
Small Integrated Quantitative Investments LLC	27,234	$378,552
Small Headlands Technologies LLC	19,814	$275,414

Filter: New 50 Increased 73 Reduced 60 Sold out 15 Unchanged 25

Showing 100 of 221

All Common Calls Puts

Compact Export CSV

Holder

Value (USD)

% of 13F

FMR LLC

$300,433,243

14.46%

16,727,909

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	14,571,467	$261,703,547	87.1%	Defined
FIDELITY MANAGEMENT TRUST CO	470,406	$8,448,491	2.8%	Defined
STRATEGIC ADVISERS LLC	85	$1,526	0.0%	Defined
Fidelity Institutional Asset Management Trust Co	314,799	$5,653,790	1.9%	Defined
FIAM LLC	1,371,152	$24,625,889	8.2%	Defined

BlackRock, Inc.

$158,534,441

7.63%

8,827,085

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	178,793	$3,211,122	2.0%	Sole
BlackRock Asset Management Canada Ltd	34,894	$626,696	0.4%	Sole
BlackRock Investment Management, LLC	283,532	$5,092,234	3.2%	Sole
BLACKROCK ADVISORS LLC	597,023	$10,722,533	6.8%	Sole
BlackRock Fund Advisors	4,523,207	$81,236,797	51.2%	Sole
BlackRock Institutional Trust Company, N.A.	2,960,827	$53,176,452	33.5%	Sole
BlackRock Japan Co. Ltd	3,062	$54,993	0.0%	Sole
BlackRock Fund Managers Ltd.	15,023	$269,813	0.2%	Sole
BlackRock (Netherlands) B.V.	13,492	$242,316	0.2%	Sole
BlackRock Asset Management Ireland Ltd	170,309	$3,058,749	1.9%	Sole
BlackRock Asset Management Schweiz AG	14,790	$265,628	0.2%	Sole
Aperio Group, LLC	32,123	$576,929	0.4%	Sole
SpiderRock Advisors, LLC	10	$179	0.0%	Sole

PERCEPTIVE ADVISORS LLC

$149,694,480

7.20%

8,334,882

TCG Crossover Management, LLC

$112,138,863

5.40%

6,243,812

Commodore Capital LP

$101,474,000

4.88%

5,650,000

Jupiter Topco LLC

$94,040,391

4.53%

5,236,102

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

Manager	Shares	Value (USD)	% of position	Discretion
JANUS HENDERSON INVESTORS UK Ltd	38,600	$693,256	0.7%	Defined
JANUS HENDERSON INVESTORS US LLC	5,197,502	$93,347,135	99.3%	Defined

Saturn V Capital Management LP

$83,048,853

4.00%

4,624,101

VANGUARD CAPITAL MANAGEMENT LLC

$75,867,063

3.65%

4,224,224

MORGAN STANLEY

$56,229,310

2.71%

3,130,808

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	2,122	$38,111	0.1%	Defined
MORGAN STANLEY & CO. LLC	344,942	$6,195,158	11.0%	Defined
MORGAN STANLEY CAPITAL SERVICES, LLC	2,705,200	$48,585,392	86.4%	Defined
MORGAN STANLEY SMITH BARNEY LLC	871	$15,643	0.0%	Defined
Morgan Stanley Bank, N.A.	12,111	$217,513	0.4%	Defined
PARAMETRIC PORTFOLIO ASSOCIATES LLC	65,562	$1,177,493	2.1%	Defined

Driehaus Capital Management LLC

$54,543,981

2.63%

3,036,970

First Light Asset Management, LLC

$54,297,677

2.61%

3,023,256

FRANKLIN RESOURCES INC

$52,986,040

2.55%

2,950,225

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

Manager	Shares	Value (USD)	% of position	Discretion
FIDUCIARY TRUST INTERNATIONAL LLC	37	$664	0.0%	Defined
FRANKLIN ADVISERS INC	2,950,188	$52,985,376	100.0%	Defined

GOLDMAN SACHS GROUP INC

$51,333,971

2.47%

2,858,239

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	1,537,612	$27,615,511	53.8%	Defined
GOLDMAN SACHS ASSET MANAGEMENT, L.P.	425,538	$7,642,662	14.9%	Defined
Goldman Sachs Trust Company, N.A.	895,089	$16,075,798	31.3%	Defined

STATE STREET CORP

$46,755,932

2.25%

2,603,337

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	2,603,337	$46,755,932	100.0%	Defined

GEODE CAPITAL MANAGEMENT, LLC

$41,942,256

2.02%

2,335,315

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	320,903	$5,763,417	13.7%	Defined
Held directly	2,014,412	$36,178,839	86.3%	Defined

ADAGE CAPITAL PARTNERS GP, L.L.C.

$34,124,000

1.64%

1,900,000

JPMORGAN CHASE & CO

$33,471,153

1.61%

1,863,650

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.	70,875	$1,272,915	3.8%	Defined
J.P. Morgan Investment Management Inc.	1,366,124	$24,535,587	73.3%	Defined
J.P. Morgan Securities plc	6,555	$117,727	0.4%	Defined
JPMorgan Asset Management (UK) Ltd	420,096	$7,544,924	22.5%	Defined

Siren, L.L.C.

$26,591,324

1.28%

1,480,586

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

Manager	Shares	Value (USD)	% of position	Discretion
Invus Group, LLC	1,480,586	$26,591,324	100.0%	Defined

EVENTIDE ASSET MANAGEMENT, LLC

$23,842,546

1.15%

1,327,536

683 Capital Management, LLC

$22,980,035

1.11%

1,279,512

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

Manager	Shares	Value (USD)	% of position	Discretion
683 Capital Partners, LP	1,279,512	$22,980,035	100.0%	Defined

VANGUARD PORTFOLIO MANAGEMENT LLC

$19,065,150

0.92%

1,061,534

Alyeska Investment Group, L.P.

$18,912,149

0.91%

1,053,015

Almitas Capital LLC

$17,508,862

0.84%

974,881

DIMENSIONAL FUND ADVISORS LP

$16,208,234

0.78%

902,463

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

Manager	Shares	Value (USD)	% of position	Discretion
Dimensional Fund Advisors Ltd.	10,802	$194,003	1.2%	Defined
DFA Australia Ltd.	25,591	$459,614	2.8%	Defined
Dimensional Ireland Ltd	56,222	$1,009,747	6.2%	Defined
Held directly	809,848	$14,544,870	89.7%	Sole

Jones Hill Capital LP

$16,057,281

0.77%

894,058

Woodline Partners LP

$15,201,110

0.73%

846,387

NORTHERN TRUST CORP

$14,938,048

0.72%

831,740

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	780,687	$14,021,138	93.9%	Defined
NORTHERN TRUST GLOBAL INVESTMENTS LTD	36,600	$657,335	4.4%	Defined
DWS INVESTMENT MANAGEMENT AMERICAS, INC joint	14,453	$259,575	1.7%	Other

BANK OF AMERICA CORP /DE/

$14,760,263

0.71%

821,841

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	537,325	$9,650,357	65.4%	Defined
MERRILL LYNCH, PIERCE, FENNER & SMITH INC.	249,387	$4,478,990	30.3%	Defined
BOFA SECURITIES, INC.	35,129	$630,916	4.3%	Defined

Boxer Capital Management, LLC

$14,368,000

0.69%

800,000

Aberdeen Group plc

$13,248,553

0.64%

737,670

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

Manager	Shares	Value (USD)	% of position	Discretion
abrdn Inc.	737,670	$13,248,553	100.0%	Defined

CHARLES SCHWAB INVESTMENT MANAGEMENT INC

$13,021,538

0.63%

725,030

Connor, Clark & Lunn Investment Management Ltd.

$12,949,195

0.62%

721,002

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

Manager	Shares	Value (USD)	% of position	Discretion
Manager 1	721,002	$12,949,195	100.0%	Sole

GREAT POINT PARTNERS LLC

$12,572,000

0.61%

700,000

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

Manager	Shares	Value (USD)	% of position	Discretion
JAY JEFFREY R joint	700,000	$12,572,000	100.0%	Defined

Balyasny Asset Management L.P.

$12,302,133

0.59%

684,974

Qube Research & Technologies Ltd

$12,237,746

0.59%

681,389

VANGUARD FIDUCIARY TRUST CO

$11,190,480

0.54%

623,078

TWO SIGMA INVESTMENTS, LP

$10,658,092

0.51%

593,435

DEUTSCHE BANK AG\

$10,020,547

0.48%

557,937

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

Manager	Shares	Value (USD)	% of position	Discretion
DWS INVESTMENT MANAGEMENT AMERICAS, INC	1,733	$31,124	0.3%	Defined
DWS Investments UK Ltd	556,204	$9,989,423	99.7%	Defined

Rock Springs Capital Management LP

$8,975,761

0.43%

499,764

ADAR1 Capital Management, LLC

$8,879,028

0.43%

494,378

Nantahala Capital Management, LLC

$8,740,844

0.42%

486,684

FEDERATED HERMES, INC.

$8,301,201

0.40%

462,205

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

Manager	Shares	Value (USD)	% of position	Discretion
FEDERATED EQUITY MANAGEMENT CO OF PENNSYLVANIA	50,305	$903,477	10.9%	Defined
FEDERATED MDTA LLC	411,900	$7,397,724	89.1%	Defined

Nearwater Capital Markets, Ltd

$7,633,000

0.37%

425,000

SUSQUEHANNA INTERNATIONAL GROUP, LLP

$7,279,188

0.35%

405,300

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

Manager	Shares	Value (USD)	% of position	Discretion
SUSQUEHANNA SECURITIES, LLC	405,300	$7,279,188	100.0%	Other

Parkman Healthcare Partners LLC

$7,162,124

0.34%

398,782

HighVista Strategies LLC

$6,933,996

0.33%

386,080

STEMPOINT CAPITAL LP

$6,902,099

0.33%

384,304

Logos Global Management LP

$6,286,000

0.30%

350,000

Trexquant Investment LP

$6,275,924

0.30%

349,439

Nuveen, LLC

$5,936,156

0.29%

330,521

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	16,120	$289,515	4.9%	Defined
TIAA CREF INVESTMENT MANAGEMENT LLC joint	57,430	$1,031,442	17.4%	Defined
TEACHERS ADVISORS, LLC joint	256,971	$4,615,199	77.7%	Defined

Ensign Peak Advisors, Inc

$5,485,720

0.26%

305,441

iA Global Asset Management Inc.

$5,455,996

0.26%

303,786

JANE STREET GROUP, LLC

$5,380,187

0.26%

299,565

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

Manager	Shares	Value (USD)	% of position	Discretion
Jane Street Capital, LLC	241,592	$4,338,992	80.6%	Defined
Jane Street Global Trading, LLC	57,973	$1,041,195	19.4%	Defined

Tetragon Partners GP Ltd

$5,350,750

0.26%

297,926

JUPITER ASSET MANAGEMENT LTD

$4,937,994

0.24%

274,944

Bank of New York Mellon Corp

$4,928,850

0.24%

274,435

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

Manager	Shares	Value (USD)	% of position	Discretion
Mellon Investments Corporation	97,949	$1,759,164	35.7%	Defined
The Bank of New York Mellon	165,971	$2,980,839	60.5%	Defined
BNY Mellon, NA joint	185	$3,322	0.1%	Defined
BNY Mellon Advisors, Inc. joint	10,329	$185,508	3.8%	Other
Held directly	1	$17	0.0%	Defined

UBS Group AG

$4,882,981

0.24%

271,881

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

Manager	Shares	Value (USD)	% of position	Discretion
UBS Financial Services Inc	1,957	$35,147	0.7%	Defined
UBS AG	268,203	$4,816,925	98.6%	Defined
UBS Securities LLC	1,721	$30,909	0.6%	Defined

FIRST TRUST ADVISORS LP

$4,572,382

0.22%

254,587

SummitTX Capital, L.P.

$4,089,312

0.20%

227,690

WELLINGTON MANAGEMENT GROUP LLP

$3,822,641

0.18%

212,842

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	66,558	$1,195,381	31.3%	Defined
Wellington Trust Company, NA joint	133,919	$2,405,185	62.9%	Defined
Wellington Management Australia Pty Ltd	12,365	$222,075	5.8%	Defined

Cormorant Asset Management, LP

$3,592,000

0.17%

200,000

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

Manager	Shares	Value (USD)	% of position	Discretion
Chen Bihua	200,000	$3,592,000	100.0%	Defined

Aldebaran Capital, LLC

$3,518,220

0.17%

195,892

Walleye Capital LLC

$3,351,120

0.16%

186,588

ORBIMED ADVISORS LLC

$3,293,864

0.16%

183,400

CITADEL ADVISORS LLC

$3,209,200

0.15%

178,686

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	111,514	$2,002,791	62.4%	Defined
Held directly	67,172	$1,206,409	37.6%	Defined

D. E. Shaw & Co., Inc.

$3,130,158

0.15%

174,285

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.	119,748	$2,150,674	68.7%	Defined
D. E. Shaw Investment Management, L.L.C. joint	54,537	$979,484	31.3%	Defined

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

$3,114,386

0.15%

173,407

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

Manager	Shares	Value (USD)	% of position	Discretion
UBS Group AG	2,297	$41,254	1.3%	Defined
UBS Asset Management Switzerland AG	128,219	$2,302,812	73.9%	Defined
UBS Asset Management (UK) Ltd.	24,362	$437,541	14.0%	Defined
Held directly	18,529	$332,779	10.7%	Defined

ACUTA CAPITAL PARTNERS, LLC

$3,019,345

0.15%

168,115

NORGES BANK

$2,871,804

0.14%

159,900

Alpha Wave Global, LP

$2,791,379

0.13%

155,422

PRICE T ROWE ASSOCIATES INC /MD/

$2,606,588

0.13%

145,133

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	145,133	$2,606,588	100.0%	Defined

Swiss National Bank

$2,589,832

0.12%

144,200

PFM Health Sciences, LP

$2,580,852

0.12%

143,700

Invesco Ltd.

$2,513,357

0.12%

139,942

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	14,084	$252,948	10.1%	Defined
Invesco Trust Co joint	36,773	$660,443	26.3%	Defined
Invesco Capital Management LLC	89,085	$1,599,966	63.7%	Defined

WELLS FARGO & COMPANY/MN

$2,301,825

0.11%

128,164

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	83,075	$1,492,027	64.8%	Defined
WELLS FARGO ADVISORS FINANCIAL NETWORK, LLC	200	$3,592	0.2%	Defined
WELLS FARGO CLEARING SERVICES, LLC	44,071	$791,515	34.4%	Defined
Wells Fargo Securities, LLC	818	$14,691	0.6%	Defined

AMERIPRISE FINANCIAL INC

$2,253,692

0.11%

125,484

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	125,484	$2,253,692	100.0%	Defined

Lighthouse Investment Partners, LLC

$2,207,445

0.11%

122,909

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

Manager	Shares	Value (USD)	% of position	Discretion
North Rock Capital Management, LLC	122,909	$2,207,445	100.0%	Defined

Ikarian Capital, LLC

$2,110,300

0.10%

117,500

RHUMBLINE ADVISERS

$2,028,043

0.10%

112,920

ALPS ADVISORS INC

$2,019,548

0.10%

112,447

Elmind Capital, LP

$2,011,520

0.10%

112,000

ALLIANCEBERNSTEIN L.P.

$1,875,024

0.09%

104,400

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

Manager	Shares	Value (USD)	% of position	Discretion
Equitable Holdings, Inc.	104,400	$1,875,024	100.0%	Defined

Campbell & CO Investment Adviser LLC

$1,813,295

0.09%

100,963

Affinity Asset Advisors, LLC

$1,778,022

0.09%

98,999

683 Capital Management, LLC

$1,734,936

0.08%

96,600

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

Manager	Shares	Value (USD)	% of position	Discretion
683 Capital Partners, LP	96,600	$1,734,936	100.0%	Defined

Russell Investments Group, Ltd.

$1,572,826

0.08%

87,574

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	60,444	$1,085,573	69.0%	Defined
Russell Investments Capital, LLC	9,732	$174,786	11.1%	Defined
Russell Investments France SAS	7,679	$137,914	8.8%	Defined
Russell Investments Trust Company	9,719	$174,553	11.1%	Defined

Quantinno Capital Management LP

$1,452,066

0.07%

80,850

CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM

$1,434,501

0.07%

79,872

1492 Capital Management LLC

$1,432,327

0.07%

79,751

CITIGROUP INC

$1,233,563

0.06%

68,684

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	68,684	$1,233,563	100.0%	Defined

Schonfeld Strategic Advisors LLC

$1,199,799

0.06%

66,804

STATE OF WISCONSIN INVESTMENT BOARD

$1,100,552

0.05%

61,278

JANE STREET GROUP, LLC

$1,079,396

0.05%

60,100

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

Manager	Shares	Value (USD)	% of position	Discretion
Jane Street Capital, LLC	60,100	$1,079,396	100.0%	Defined

Corient Private Wealth LLC

$1,065,423

0.05%

59,322

Moody Aldrich Partners LLC

$1,038,123

0.05%

57,802

VANGUARD ASSET MANAGEMENT, Ltd

$1,022,786

0.05%

56,948

Legal & General Group Plc

$1,014,326

0.05%

56,477

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

Manager	Shares	Value (USD)	% of position	Discretion
Legal & General Investment Management America Inc	8,930	$160,382	15.8%	Defined
Legal & General Investment Management Ltd joint	47,547	$853,944	84.2%	Defined

BARCLAYS PLC

$1,010,393

0.05%

56,258

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

Manager	Shares	Value (USD)	% of position	Discretion
BARCLAYS BANK PLC	53,917	$968,349	95.8%	Defined
BARCLAYS CAPITAL INC.	2,341	$42,044	4.2%	Defined

MetLife Investment Management, LLC

$1,000,372

0.05%

55,700

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

Manager	Shares	Value (USD)	% of position	Discretion
METLIFE INC	55,700	$1,000,372	100.0%	Defined

SG Americas Securities, LLC

$993,565

0.05%

55,321

Key facts CIK 1658551 CUSIP 03237H101 13F (30d) 165 filings 165 filers Visit website Investor relations