Who owns Amylyx Pharmaceuticals (AMLX)
Which tracked institutional funds hold AMLX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See AMLX company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on AMLX is one-sided between 2026-Q1 and 2026-Q2: 84 added or opened and 23 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
AMLX’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in AMLX divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 200 tracked filers holding AMLX, 119 increased or opened the position and 77 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in AMLX between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 25
- Jupiter Topco LLC$94M
- Alyeska Investment Group, L.P.$19M
- Aberdeen Group plc$13M
- Nearwater Capital Markets, Ltd$8M
- Trexquant Investment LP$6M
- Ensign Peak Advisors, Inc$5M
Full exits 5
- JANUS HENDERSON GROUP PLC$69M
- iA Global Asset Management Inc.$4M
- Squarepoint Ops LLC$2M
- Point72 Asset Management, L.P.$1M
- Informed Momentum Co LLC$740K
Largest adds
- FMR LLC$80M
- BlackRock, Inc.$36M
- PERCEPTIVE ADVISORS LLC$35M
- JPMORGAN CHASE & CO$33M
- MORGAN STANLEY$26M
- TCG Crossover Management, LLC$25M
Largest trims
- ADAGE CAPITAL PARTNERS GP, L.L.C.$15M
- BARCLAYS PLC$12M
- Almitas Capital LLC$12M
- GREAT POINT PARTNERS LLC$12M
- DEUTSCHE BANK AG\$8M
- Jones Hill Capital LP$6M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 16,727,909 | $300M | 14.7% | 2026-Q2 |
| BlackRock, Inc. trimmed | 8,827,085 | $159M | 7.8% | 2026-Q2 |
| PERCEPTIVE ADVISORS LLC added | 8,334,882 | $150M | 7.3% | 2026-Q2 |
| TCG Crossover Management, LLC | 6,243,812 | $112M | 5.5% | 2026-Q2 |
| Commodore Capital LP | 5,650,000 | $101M | 5.0% | 2026-Q2 |
| Jupiter Topco LLC new | 5,236,102 | $94M | 4.6% | 2026-Q2 |
| Saturn V Capital Management LP added | 4,624,101 | $83M | 4.1% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 4,224,224 | $76M | 3.7% | 2026-Q2 |
| MORGAN STANLEY added | 3,130,808 | $56M | 2.8% | 2026-Q2 |
| Driehaus Capital Management LLC added | 3,036,970 | $55M | 2.7% | 2026-Q2 |
| First Light Asset Management, LLC trimmed | 3,023,256 | $54M | 2.7% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 2,950,225 | $53M | 2.6% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 2,858,239 | $51M | 2.5% | 2026-Q2 |
| STATE STREET CORP added | 2,603,337 | $47M | 2.3% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,335,315 | $42M | 2.1% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 1,900,000 | $34M | 1.7% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 1,863,650 | $35M | 1.7% | 2026-Q2 |
| Siren, L.L.C. added | 1,480,586 | $27M | 1.3% | 2026-Q2 |
| EVENTIDE ASSET MANAGEMENT, LLC trimmed | 1,327,536 | $24M | 1.2% | 2026-Q2 |
| 683 Capital Management, LLC trimmed | 1,279,512 | $23M | 1.1% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 1,061,534 | $19M | 0.9% | 2026-Q2 |
| Alyeska Investment Group, L.P. added | 1,053,015 | $19M | 0.9% | 2026-Q2 |
| Almitas Capital LLC trimmed | 974,881 | $18M | 0.9% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 902,463 | $16M | 0.8% | 2026-Q2 |
| Jones Hill Capital LP trimmed | 894,058 | $16M | 0.8% | 2026-Q2 |
| Woodline Partners LP added | 846,387 | $15M | 0.7% | 2026-Q2 |
| NORTHERN TRUST CORP added | 831,740 | $15M | 0.7% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 821,841 | $15M | 0.7% | 2026-Q2 |
| Boxer Capital Management, LLC | 800,000 | $14M | 0.7% | 2026-Q2 |
| Aberdeen Group plc trimmed | 737,670 | $13M | 0.7% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 725,030 | $13M | 0.6% | 2026-Q2 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 721,002 | $13M | 0.6% | 2026-Q2 |
| GREAT POINT PARTNERS LLC trimmed | 700,000 | $13M | 0.6% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 684,974 | $12M | 0.6% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 681,389 | $12M | 0.6% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 623,078 | $11M | 0.5% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 593,435 | $11M | 0.5% | 2026-Q2 |
| DEUTSCHE BANK AG\ trimmed | 557,937 | $10M | 0.5% | 2026-Q2 |
| Rock Springs Capital Management LP | 499,764 | $9M | 0.4% | 2026-Q2 |
| ADAR1 Capital Management, LLC trimmed | 494,378 | $9M | 0.4% | 2026-Q2 |
| Nantahala Capital Management, LLC trimmed | 486,684 | $9M | 0.4% | 2026-Q2 |
| FEDERATED HERMES, INC. added | 462,205 | $8M | 0.4% | 2026-Q2 |
| Nearwater Capital Markets, Ltd new | 425,000 | $8M | 0.4% | 2026-Q2 |
| Parkman Healthcare Partners LLC trimmed | 398,782 | $7M | 0.4% | 2026-Q2 |
| HighVista Strategies LLC added | 386,080 | $7M | 0.3% | 2026-Q2 |
| STEMPOINT CAPITAL LP trimmed | 384,304 | $7M | 0.3% | 2026-Q2 |
| Logos Global Management LP trimmed | 350,000 | $6M | 0.3% | 2026-Q2 |
| Trexquant Investment LP added | 349,439 | $6M | 0.3% | 2026-Q2 |
| Nuveen, LLC added | 330,521 | $6M | 0.3% | 2026-Q2 |
| Ensign Peak Advisors, Inc new | 305,441 | $5M | 0.3% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 299,565 | $5M | 0.3% | 2026-Q2 |
| Tetragon Partners GP Ltd trimmed | 297,926 | $5M | 0.3% | 2026-Q2 |
| JUPITER ASSET MANAGEMENT LTD trimmed | 274,944 | $5M | 0.2% | 2026-Q2 |
| Bank of New York Mellon Corp added | 274,435 | $5M | 0.2% | 2026-Q2 |
| UBS Group AG trimmed | 271,881 | $5M | 0.2% | 2026-Q2 |
| FIRST TRUST ADVISORS LP added | 254,587 | $5M | 0.2% | 2026-Q2 |
| SummitTX Capital, L.P. added | 227,690 | $4M | 0.2% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 212,842 | $4M | 0.2% | 2026-Q2 |
| Cormorant Asset Management, LP trimmed | 200,000 | $4M | 0.2% | 2026-Q2 |
| Aldebaran Capital, LLC trimmed | 195,892 | $4M | 0.2% | 2026-Q2 |
| Walleye Capital LLC added | 186,588 | $3M | 0.2% | 2026-Q2 |
| ORBIMED ADVISORS LLC trimmed | 183,400 | $3M | 0.2% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 178,686 | $3M | 0.2% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 174,285 | $3M | 0.2% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 173,407 | $3M | 0.2% | 2026-Q2 |
| ACUTA CAPITAL PARTNERS, LLC added | 168,115 | $3M | 0.1% | 2026-Q2 |
| NORGES BANK new | 159,900 | $3M | 0.1% | 2026-Q2 |
| Alpha Wave Global, LP added | 155,422 | $3M | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 145,133 | $3M | 0.1% | 2026-Q2 |
| Swiss National Bank added | 144,200 | $3M | 0.1% | 2026-Q2 |
| PFM Health Sciences, LP trimmed | 143,700 | $3M | 0.1% | 2026-Q2 |
| Invesco Ltd. trimmed | 139,942 | $3M | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 128,164 | $2M | 0.1% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC trimmed | 125,484 | $2M | 0.1% | 2026-Q2 |
| Lighthouse Investment Partners, LLC new | 122,909 | $2M | 0.1% | 2026-Q2 |
| Ikarian Capital, LLC trimmed | 117,500 | $2M | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 112,920 | $2M | 0.1% | 2026-Q2 |
| ALPS ADVISORS INC added | 112,447 | $2M | 0.1% | 2026-Q2 |
| Elmind Capital, LP | 112,000 | $2M | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 104,400 | $1M | 0.1% | 2026-Q2 |
| Campbell & CO Investment Adviser LLC added | 100,963 | $2M | 0.1% | 2026-Q2 |
| Affinity Asset Advisors, LLC new | 98,999 | $2M | 0.1% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 87,574 | $2M | 0.1% | 2026-Q2 |
| Quantinno Capital Management LP new | 80,850 | $1M | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 79,872 | $1M | 0.1% | 2026-Q2 |
| 1492 Capital Management LLC new | 79,751 | $1M | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 68,684 | $1M | 0.1% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC trimmed | 66,804 | $1M | 0.1% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 61,278 | $1M | 0.1% | 2026-Q2 |
| Corient Private Wealth LP new | 59,322 | $1M | 0.1% | 2026-Q2 |
| Moody Aldrich Partners LLC new | 57,802 | $1M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 56,948 | $1M | 0.1% | 2026-Q2 |
| Legal & General Group Plc added | 56,477 | $1M | 0.0% | 2026-Q2 |
| BARCLAYS PLC trimmed | 56,258 | $1M | 0.0% | 2026-Q2 |
| MetLife Investment Management, LLC added | 55,700 | $1M | 0.0% | 2026-Q2 |
| Hudson Bay Capital Management LP added | 50,000 | $898K | 0.0% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 47,851 | $859K | 0.0% | 2026-Q2 |
| FOX RUN MANAGEMENT, L.L.C. added | 44,817 | $805K | 0.0% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. trimmed | 42,351 | $761K | 0.0% | 2026-Q2 |
| Aquatic Capital Management LLC added | 39,425 | $708K | 0.0% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.