AMYLYX PHARMACEUTICALS INC AMLX
COM · Common Stock · CUSIP 03237H101
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersCambridge, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($112.9k this quarter). Holder counts are more reliable. Shares outstanding: 111.2m as of 2026-04-27, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $13.90. Options: 8 managers hold calls ($9.0m notional), 7 hold puts ($1.5m).
Trends to Q1 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 95 |
| Q4 2022 | 135 |
| Q1 2023 | 149 |
| Q2 2023 | 156 |
| Q3 2023 | 171 |
| Q4 2023 | 179 |
| Q1 2024 | 144 |
| Q2 2024 | 120 |
| Q3 2024 | 111 |
| Q4 2024 | 123 |
| Q1 2025 | 137 |
| Q2 2025 | 132 |
| Q3 2025 | 169 |
| Q4 2025 | 180 |
| Q1 2026 | 171 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 60 | 97 |
| Q3 2024 | 54 | 66 |
| Q4 2024 | 62 | 60 |
| Q1 2025 | 79 | 47 |
| Q2 2025 | 67 | 72 |
| Q3 2025 | 102 | 67 |
| Q4 2025 | 107 | 72 |
| Q1 2026 | 84 | 89 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $1.5m | $102.9k | 0.07 |
| Q3 2025 | $7.3m | $2.2m | 0.29 |
| Q4 2025 | $6.4m | $775.5k | 0.12 |
| Q1 2026 | $9.0m | $1.5m | 0.17 |
Biggest buyers
| Siren, L.L.C. | New | +1.2m |
| FRANKLIN RESOURCES INC | Added | +1.1m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Added | +783.7k |
| STEMPOINT CAPITAL LP | Added | +774.2k |
| BARCLAYS PLC | Added | +676.7k |
| JUPITER ASSET MANAGEMENT LTD | Added | +577.1k |
| JANUS HENDERSON GROUP PLC | Added | +520.2k |
| iA Global Asset Management Inc. | New | +304.8k |
| STATE STREET CORP | Added | +293.3k |
| Qube Research & Technologies Ltd | Added | +289.4k |
Biggest sellers
| Sofinnova Investments, Inc. | Sold out | -527.1k |
| SILVERARC CAPITAL MANAGEMENT, LLC | Sold out | -506.2k |
| AMERIPRISE FINANCIAL INC | Sold out | -502.4k |
| Patient Square Capital LP | Sold out | -350.0k |
| TWO SIGMA ADVISERS, LP | Sold out | -328.4k |
| Nantahala Capital Management, LLC | Reduced | -300.0k |
| JANE STREET GROUP, LLC | Sold out | -263.2k |
| ACADIAN ASSET MANAGEMENT LLC | Sold out | -254.3k |
| Logos Global Management LP | Reduced | -250.0k |
| Point72 Asset Management, L.P. | Reduced | -228.5k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.5m253.9k shares |
| GROUP ONE TRADING LLC | Reduced | $2.6m185.8k shares |
| 683 Capital Management, LLC | New | $1.3m96.6k shares |
| CITADEL ADVISORS LLC | Reduced | $629.7k45.3k shares |
| SIMPLEX TRADING, LLC | Added | $454.5k32.7k shares |
| Belvedere Trading LLC | Added | $204.3k14.7k shares |
| JANE STREET GROUP, LLC | Reduced | $190.4k13.7k shares |
| Walleye Capital LLC | Reduced | $87.6k6.3k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $838.2k60.3k shares |
| CITADEL ADVISORS LLC | New | $177.9k12.8k shares |
| SIMPLEX TRADING, LLC | Added | $165.4k11.9k shares |
| JANE STREET GROUP, LLC | Added | $165.4k11.9k shares |
| GROUP ONE TRADING LLC | Reduced | $84.8k6.1k shares |
| Belvedere Trading LLC | Added | $40.3k2.9k shares |
| Walleye Capital LLC | Reduced | $25.0k1.8k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution +4.3 pts · filed 2026-02-05 | 15.0% |
| PERCEPTIVE ADVISORS LLC 13G · passive investor -0.7 pts · filed 2026-05-15 | 7.5% |
| BlackRock, Inc. 13G · institution +1.6 pts · filed 2026-01-21 | 7.1% |
| TCG Crossover GP II, LLC 13G · passive investor filed 2026-02-17 | 5.7% |
| Commodore Capital LP 13G · passive investor new · filed 2025-11-17 | 5.1% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26), Adage Capital Management, L.P. (2.5%, 2026-02-12), Point72 Asset Management, L.P. (2.6%, 2025-11-14)
Insider purchases and sales in Q1 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q2 2024 | 1 | $9.4k | 1 | $19.7k | $19.7k |
| Q3 2024 | 3 | $427.7k | 4 | $124.0k | — |
| Q4 2024 | 0 | — | 1 | $30.0k | — |
| Q1 2025 | 1 | $37.0k | 5 | $464.6k | — |
| Q2 2025 | 0 | — | 0 | — | — |
| Q3 2025 | 0 | — | 5 | $1.6m | $246.2k |
| Q4 2025 | 1 | $100.8k | 1 | $94.4k | — |
| Q1 2026 | 0 | — | 5 | $5.6m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-02 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $424.0k29.3k shares |
| 2026-03-02 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $423.7k29.3k shares |
| 2026-03-02 | FRATES JAMES M Chief Financial Officer | Sold | $114.8k7.9k shares |
| 2026-03-02 | Mazzariello Gina Chief Legal Officer | Sold | $99.4k6.8k shares |
| 2026-03-02 | Bedrosian Camille L Chief Medical Officer | Sold | $94.2k6.5k shares |
| 2026-02-23 | Mazzariello Gina Chief Legal Officer | Sold | $48.3k3.4k shares |
| 2026-02-02 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $227.7k15.5k shares |
| 2026-02-02 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $227.5k15.5k shares |
| 2026-02-02 | FRATES JAMES M Chief Financial Officer | Sold | $52.1k3.6k shares |
| 2026-02-02 | Mazzariello Gina Chief Legal Officer | Sold | $50.5k3.4k shares |
| 2026-01-16 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $27.7k2.0k shares |
| 2026-01-16 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $27.3k2.0k shares |
| 2026-01-15 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $1.9m136.2k shares |
| 2026-01-15 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $1.8m136.2k shares |
| 2026-01-06 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $85.6k7.7k shares |
| 2026-01-06 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $85.6k7.7k shares |
| 2026-01-06 | FRATES JAMES M Chief Financial Officer | Sold | $37.0k3.3k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.01% of their portfolio | 16.6m $231.2m | Added +112.1k |
| BlackRock, Inc. 0.00% of their portfolio | 8.8m $122.7m | Reduced -225.6k |
| PERCEPTIVE ADVISORS LLC 2.27% of their portfolio | 8.3m $115.2m | Unchanged |
| TCG Crossover Management, LLC 2.48% of their portfolio | 6.2m $86.8m | Unchanged |
| Commodore Capital LP 4.54% of their portfolio | 5.7m $78.5m | Unchanged |
| JANUS HENDERSON GROUP PLC 0.03% of their portfolio | 5.0m $69.3m | Added +520.2k |
| Saturn V Capital Management LP 10.95% of their portfolio | 4.3m $60.5m | Reduced -146.6k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 4.1m $57.6m | First filing |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.08% of their portfolio | 3.6m $49.5m | Added +783.7k |
| First Light Asset Management, LLC 3.97% of their portfolio | 3.2m $44.3m | Reduced -164.9k |
| Driehaus Capital Management LLC 0.31% of their portfolio | 3.0m $41.5m | Reduced -122.4k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.6m $36.5m | Added +12.8k |
| STATE STREET CORP 0.00% of their portfolio | 2.4m $32.8m | Added +293.3k |
| FRANKLIN RESOURCES INC 0.01% of their portfolio | 2.3m $31.4m | Added +1.1m |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 2.2m $30.7m | Added +45.4k |
| MORGAN STANLEY 0.00% of their portfolio | 2.2m $30.2m | Reduced -184.3k |
| Almitas Capital LLC 6.67% of their portfolio | 2.1m $29.5m | Unchanged |
| GREAT POINT PARTNERS LLC 5.96% of their portfolio | 1.8m $24.3m | Unchanged |
| Jones Hill Capital LP 4.76% of their portfolio | 1.6m $22.2m | First filing |
| 683 Capital Management, LLC 1.97% of their portfolio | 1.5m $21.3m | Reduced -120.0k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.35% of their portfolio | 1.5m $21.0m | Added +810 |
| STEMPOINT CAPITAL LP 1.80% of their portfolio | 1.3m $18.6m | Added +774.2k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 1.3m $18.5m | Reduced -5.3k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 1.3m $17.6m | Reduced -65.5k |
| Siren, L.L.C. 0.47% of their portfolio | 1.2m $17.1m | New |
| Balyasny Asset Management L.P. 0.03% of their portfolio | 1.1m $15.4m | Added +248.6k |
| ADAR1 Capital Management, LLC 0.84% of their portfolio | 1.0m $13.9m | Added +110.2k |
| BARCLAYS PLC 0.00% of their portfolio | 971.9k $13.5m | Added +676.7k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 944.8k $13.1m | First filing |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 903.2k $12.5m | Added +131.9k |
| Connor, Clark & Lunn Investment Management Ltd. 0.03% of their portfolio | 868.3k $12.1m | Reduced -135.7k |
| Woodline Partners LP 0.04% of their portfolio | 845.8k $11.8m | Added +392 |
| Boxer Capital Management, LLC 1.46% of their portfolio | 800.0k $11.1m | Unchanged |
| NORTHERN TRUST CORP 0.00% of their portfolio | 779.9k $10.8m | Reduced -157.9k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 716.2k $10.0m | Added +3.2k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 702.2k $9.8m | Added +289.4k |
| Logos Global Management LP 0.50% of their portfolio | 700.0k $9.7m | Reduced -250.0k |
| Parkman Healthcare Partners LLC 0.90% of their portfolio | 621.5k $8.6m | Added +239.7k |
| JUPITER ASSET MANAGEMENT LTD 0.04% of their portfolio | 592.7k $8.2m | Added +577.1k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 586.2k $8.1m | First filing |
| Nantahala Capital Management, LLC 0.46% of their portfolio | 535.7k $7.4m | Reduced -300.0k |
| Rock Springs Capital Management LP 0.41% of their portfolio | 499.8k $6.9m | Unchanged |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 411.5k $5.7m | Added +66.6k |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 363.5k $5.1m | Reduced -93.9k |
| HighVista Strategies LLC 1.35% of their portfolio | 352.1k $4.9m | Added +113.3k |
| Cormorant Asset Management, LP 0.25% of their portfolio | 350.0k $4.9m | Reduced -50.0k |
| UBS Group AG 0.00% of their portfolio | 324.3k $4.5m | Reduced -219.0k |
| Tetragon Partners GP Ltd 0.87% of their portfolio | 317.9k $4.4m | Added +45.0k |
| iA Global Asset Management Inc. 0.06% of their portfolio | 304.8k $4.2m | New |
| Nuveen, LLC 0.00% of their portfolio | 264.9k $3.7m | Reduced -19.1k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 251.1k $3.5m | Added +33.8k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 241.6k $3.4m | Added +15.8k |
| SummitTX Capital, L.P. 0.10% of their portfolio | 227.0k $3.2m | Added +8.6k |
| Aldebaran Capital, LLC 2.10% of their portfolio | 197.9k $2.8m | Reduced -616 |
| Invesco Ltd. 0.00% of their portfolio | 171.6k $2.4m | Reduced -4.3k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 161.9k $2.3m | Reduced -182.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 159.7k $2.0m | Added +93.1k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 157.1k $2.2m | Added +58.3k |
| ACUTA CAPITAL PARTNERS, LLC 1.49% of their portfolio | 151.1k $2.1m | Reduced -182.2k |
| PFM Health Sciences, LP 0.21% of their portfolio | 145.3k $2.0m | Added +10.7k |
| Alpha Wave Global, LP 0.25% of their portfolio | 142.3k $2.0m | Reduced -175.3k |
| Swiss National Bank 0.00% of their portfolio | 130.3k $1.8m | Reduced -31.4k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 121.4k $1.7m | Added +13.9k |
| Squarepoint Ops LLC 0.00% of their portfolio | 114.9k $1.6m | Added +38.3k |
| Elmind Capital, LP 0.44% of their portfolio | 112.0k $1.6m | Unchanged |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 108.5k $1.5m | Added +9.2k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 106.5k $1.5m | Reduced -228.5k |
| ALPS ADVISORS INC 0.01% of their portfolio | 90.0k $1.3m | Reduced -189 |
| SEI INVESTMENTS CO 0.00% of their portfolio | 85.3k $1.2m | Added +32.4k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 80.8k $976.1k | Added +9.3k |
| Schonfeld Strategic Advisors LLC 0.01% of their portfolio | 77.8k $1.1m | Added +56.7k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 75.1k $1.0m | Reduced -71.2k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 74.2k $1.0m | Added +1.0k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 72.1k $1.0m | Reduced -12.1k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 65.0k $903.5k | Reduced -14.1k |
| Walleye Capital LLC 0.01% of their portfolio | 61.7k $857.8k | Added +56.0k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 59.3k $824.9k | Reduced -6.1k |
| Legal & General Group Plc 0.00% of their portfolio | 55.8k $775.2k | Reduced -16.8k |
| Campbell & CO Investment Adviser LLC 0.04% of their portfolio | 54.4k $756.5k | Reduced -24.3k |
| Informed Momentum Co LLC 0.09% of their portfolio | 53.3k $740.3k | Unchanged |
| MetLife Investment Management, LLC 0.00% of their portfolio | 51.6k $717.1k | Added +1.9k |
| Maven Securities LTD 0.06% of their portfolio | 50.0k $695.0k | New |
| Numerai GP LLC 0.07% of their portfolio | 48.6k $674.9k | Reduced -64.1k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 47.9k $665.1k | First filing |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 43.3k $601.6k | First filing |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 42.6k $591.5k | Added +1.4k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 40.8k $567.0k | Added +4.9k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 39.8k $553.2k | Reduced -29.1k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 38.8k $539.1k | Added +11.8k |
| OPTIMIZE FINANCIAL INC. 0.22% of their portfolio | 32.0k $444.8k | New |
| CITIGROUP INC 0.00% of their portfolio | 31.8k $441.8k | Reduced -6.2k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 31.3k $435.5k | Added +8.9k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 29.1k $404.3k | Added +1.2k |
| Integrated Quantitative Investments LLC 0.07% of their portfolio | 27.2k $378.6k | Unchanged |
| GUGGENHEIM CAPITAL LLC 0.00% of their portfolio | 25.5k $354.6k | Added +270 |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 24.9k $346.4k | Reduced -7.1k |
| Vanguard Personalized Indexing Management, LLC 0.00% of their portfolio | 24.1k $334.6k | Added +3.2k |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 23.8k $330.2k | Unchanged |
| State of New Jersey Common Pension Fund D 0.00% of their portfolio | 22.5k $313.0k | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 21.9k $304.4k | Unchanged |