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 ($342.3k this quarter). Holder counts are more reliable. Shares outstanding: 109.8m as of 2025-10-27, 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 ≈ $13.59. Options: 7 managers hold calls ($7.3m notional), 5 hold puts ($2.2m).
Trends to Q3 2025
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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2023 | 110 | 72 |
| Q1 2024 | 80 | 106 |
| Q2 2024 | 60 | 97 |
| Q3 2024 | 54 | 66 |
| Q4 2024 | 62 | 60 |
| Q1 2025 | 79 | 47 |
| Q2 2025 | 67 | 72 |
| Q3 2025 | 102 | 67 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q4 2024 | $1.4m | $1.9m | 1.43 |
| Q1 2025 | $524.4k | $605.5k | 1.15 |
| Q2 2025 | $1.5m | $102.9k | 0.07 |
| Q3 2025 | $7.3m | $2.2m | 0.29 |
Biggest buyers
| FMR LLC | Added | +8.3m |
| Commodore Capital LP | New | +4.1m |
| First Light Asset Management, LLC | New | +3.4m |
| JANUS HENDERSON GROUP PLC | New | +2.5m |
| Almitas Capital LLC | Added | +2.1m |
| Paradigm Biocapital Advisors LP | New | +1.9m |
| BlackRock, Inc. | Added | +1.6m |
| EVENTIDE ASSET MANAGEMENT, LLC | New | +1.5m |
| Balyasny Asset Management L.P. | New | +1.5m |
| MORGAN STANLEY | Added | +1.5m |
Biggest sellers
| Nantahala Capital Management, LLC | Reduced | -2.0m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -2.0m |
| Point72 Asset Management, L.P. | Reduced | -1.7m |
| MILLENNIUM MANAGEMENT LLC | Reduced | -1.1m |
| CITADEL ADVISORS LLC | Reduced | -1.0m |
| Aberdeen Group plc | Sold out | -738.7k |
| Schonfeld Strategic Advisors LLC | Reduced | -602.8k |
| TWO SIGMA INVESTMENTS, LP | Reduced | -460.4k |
| 683 Capital Management, LLC | Reduced | -400.0k |
| RENAISSANCE TECHNOLOGIES LLC | Reduced | -376.3k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $2.7m196.4k shares |
| CITADEL ADVISORS LLC | Added | $1.3m98.1k shares |
| SIMPLEX TRADING, LLC | Added | $971.0k71.5k shares |
| GROUP ONE TRADING LLC | Added | $913.2k67.2k shares |
| JANE STREET GROUP, LLC | New | $713.5k52.5k shares |
| WOLVERINE TRADING, LLC | New | $408.3k27.4k shares |
| Walleye Capital LLC | New | $301.7k22.2k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $1.4m101.2k shares |
| CITADEL ADVISORS LLC | New | $530.0k39.0k shares |
| SIMPLEX TRADING, LLC | Added | $130.0k9.6k shares |
| Walleye Capital LLC | New | $92.4k6.8k shares |
| GROUP ONE TRADING LLC | Added | $24.5k1.8k 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)
Insider purchases and sales in Q3 2025
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 |
|---|---|---|---|---|---|
| Q4 2023 | 1 | $59.9k | 0 | — | — |
| Q1 2024 | 0 | — | 5 | $378.8k | — |
| 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 |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-09-30 | Klee Justin B. Co-Chief Executive Officer, director | Sold | $430.9k30.0k shares |
| 2025-09-30 | Cohen Joshua B Co-Chief Executive Officer, director | Sold | $429.4k29.9k shares |
| 2025-09-30 | Bedrosian Camille L Chief Medical Officer | Sold | $175.5k12.0k shares |
| 2025-09-30 | FRATES JAMES M Chief Financial Officer | Sold | $154.7k10.6k shares |
| 2025-09-30 | Mazzariello Gina Chief Legal Officer | Sold | $128.7k8.8k shares |
| 2025-08-13 | Mazzariello Gina Chief Legal Officer | Sold plan | $125.1k15.0k shares |
| 2025-08-12 | Mazzariello Gina Chief Legal Officer | Sold plan | $121.0k15.0k 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, Q3 2025
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.01% of their portfolio | 11.4m $154.6m | Added +8.3m |
| PERCEPTIVE ADVISORS LLC 3.52% of their portfolio | 9.0m $121.7m | Added +1.1m |
| BlackRock, Inc. 0.00% of their portfolio | 7.1m $97.0m | Added +1.6m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.15% of their portfolio | 6.8m $92.6m | Reduced -2.0m |
| TCG Crossover Management, LLC 4.17% of their portfolio | 6.2m $84.9m | Added +300.0k |
| VANGUARD GROUP INC 0.00% of their portfolio | 5.3m $71.7m | Added +775.7k |
| Saturn V Capital Management LP 13.72% of their portfolio | 4.6m $62.6m | Added +1.3m |
| Almitas Capital LLC 6.66% of their portfolio | 4.2m $57.7m | Added +2.1m |
| Commodore Capital LP 2.70% of their portfolio | 4.1m $55.4m | New |
| First Light Asset Management, LLC 4.30% of their portfolio | 3.4m $45.6m | New |
| Point72 Asset Management, L.P. 0.08% of their portfolio | 2.8m $37.9m | Reduced -1.7m |
| JANUS HENDERSON GROUP PLC 0.02% of their portfolio | 2.5m $34.5m | New |
| Driehaus Capital Management LLC 0.24% of their portfolio | 2.4m $32.9m | Added +1.2m |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.0m $27.3m | Added +712.7k |
| MORGAN STANLEY 0.00% of their portfolio | 2.0m $26.5m | Added +1.5m |
| Paradigm Biocapital Advisors LP 0.76% of their portfolio | 1.9m $25.8m | New |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.8m $24.6m | Added +119.6k |
| 683 Capital Management, LLC 2.17% of their portfolio | 1.8m $23.9m | Reduced -400.0k |
| GREAT POINT PARTNERS LLC 9.65% of their portfolio | 1.7m $23.1m | Reduced -300.0k |
| STATE STREET CORP 0.00% of their portfolio | 1.6m $22.0m | Added +612.4k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.34% of their portfolio | 1.5m $20.6m | New |
| Balyasny Asset Management L.P. 0.04% of their portfolio | 1.5m $20.1m | New |
| Logos Global Management LP 1.95% of their portfolio | 1.4m $19.7m | New |
| UBS Group AG 0.00% of their portfolio | 1.4m $19.1m | Added +151.1k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 1.4m $18.6m | Added +748.6k |
| T. Rowe Price Investment Management, Inc. 0.01% of their portfolio | 1.2m $16.3m | New |
| Connor, Clark & Lunn Investment Management Ltd. 0.05% of their portfolio | 1.1m $15.0m | Reduced -47.5k |
| Nantahala Capital Management, LLC 0.79% of their portfolio | 935.7k $12.7m | Reduced -2.0m |
| Boxer Capital Management, LLC 3.90% of their portfolio | 900.0k $12.2m | Reduced -325.0k |
| ADAR1 Capital Management, LLC 1.17% of their portfolio | 866.2k $11.8m | Reduced -338.9k |
| Woodline Partners LP 0.05% of their portfolio | 845.3k $11.5m | Reduced -355.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 822.2k $11.2m | Added +2.1k |
| Invesco Ltd. 0.00% of their portfolio | 810.6k $11.0m | Added +223.8k |
| ORBIMED ADVISORS LLC 0.24% of their portfolio | 750.6k $10.2m | Added +437.4k |
| SILVERARC CAPITAL MANAGEMENT, LLC 1.38% of their portfolio | 700.0k $9.5m | New |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 645.2k $8.8m | Added +56.8k |
| BRAIDWELL LP 0.25% of their portfolio | 612.8k $8.3m | New |
| Parkman Healthcare Partners LLC 0.86% of their portfolio | 579.2k $7.9m | Reduced -70.8k |
| JENNISON ASSOCIATES LLC 0.00% of their portfolio | 578.7k $7.9m | New |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 509.8k $6.9m | Added +136.0k |
| Cormorant Asset Management, LP 0.47% of their portfolio | 500.0k $6.8m | New |
| Rock Springs Capital Management LP 0.40% of their portfolio | 499.8k $6.8m | Unchanged |
| Ally Bridge Group (NY) LLC 4.98% of their portfolio | 437.4k $5.9m | New |
| PFM Health Sciences, LP 0.51% of their portfolio | 436.2k $5.9m | Reduced -296.1k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 429.5k $5.8m | Reduced -22.3k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 417.8k $5.7m | Reduced -1.1m |
| BARCLAYS PLC 0.00% of their portfolio | 414.1k $5.6m | Added +283.8k |
| ACADIAN ASSET MANAGEMENT LLC 0.01% of their portfolio | 367.3k $5.0m | Reduced -201.8k |
| ACUTA CAPITAL PARTNERS, LLC 4.68% of their portfolio | 333.3k $4.5m | New |
| Alpha Wave Global, LP 0.45% of their portfolio | 327.3k $4.4m | Added +51.5k |
| Patient Square Capital LP 1.15% of their portfolio | 316.3k $4.3m | New |
| STEMPOINT CAPITAL LP 0.76% of their portfolio | 276.9k $3.8m | New |
| Tetragon Partners GP Ltd 0.51% of their portfolio | 258.2k $3.5m | Added +39.5k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 236.2k $3.2m | Reduced -52.4k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 234.7k $3.2m | Reduced -1.0m |
| Trexquant Investment LP 0.03% of their portfolio | 222.9k $3.0m | New |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 212.4k $2.9m | Added +8.4k |
| Aldebaran Capital, LLC 2.55% of their portfolio | 204.5k $2.8m | Reduced -13.4k |
| Longaeva Partners L.P. 0.58% of their portfolio | 200.0k $2.7m | New |
| Bank of New York Mellon Corp 0.00% of their portfolio | 183.0k $2.5m | Added +32.1k |
| SummitTX Capital, L.P. 0.09% of their portfolio | 168.0k $2.3m | New |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 167.1k $2.3m | Reduced -270.9k |
| FRED ALGER MANAGEMENT, LLC 0.01% of their portfolio | 164.0k $2.2m | New |
| Nuveen, LLC 0.00% of their portfolio | 160.4k $2.2m | Added +4.9k |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 143.8k $2.0m | Added +240 |
| TWO SIGMA ADVISERS, LP 0.00% of their portfolio | 143.0k $1.9m | Reduced -327.0k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 133.5k $1.8m | Added +38.3k |
| Kennondale Capital Management LLC 1.13% of their portfolio | 108.6k $1.5m | Added +13.4k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 100.4k $1.4m | Added +9.1k |
| TANG CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 100.0k $1.4m | Unchanged |
| DIADEMA PARTNERS LP 0.95% of their portfolio | 100.0k $1.4m | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 98.7k $1.3m | Reduced -1.9k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 98.4k $1.3m | Reduced -460.4k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 93.7k $1.3m | Added +55.6k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 93.0k $1.3m | Added +68.7k |
| DARK FOREST CAPITAL MANAGEMENT LP 0.04% of their portfolio | 86.8k $1.2m | New |
| Informed Momentum Co LLC 0.12% of their portfolio | 75.1k $1.0m | Reduced -24.8k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 73.6k $1.0m | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 71.7k $974.2k | Reduced -16.3k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 71.5k $971.7k | Added +40.9k |
| Maven Securities LTD 0.18% of their portfolio | 70.0k $951.3k | New |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 68.9k $936.0k | Reduced -82.6k |
| Legal & General Group Plc 0.00% of their portfolio | 67.2k $913.4k | Added +59.8k |
| Numerai GP LLC 0.13% of their portfolio | 67.2k $912.6k | New |
| Verition Fund Management LLC 0.00% of their portfolio | 63.9k $868.3k | New |
| READYSTATE ASSET MANAGEMENT LP 0.04% of their portfolio | 59.1k $803.6k | New |
| Brevan Howard Capital Management LP 0.01% of their portfolio | 56.7k $770.1k | New |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 55.4k $753.0k | Added +49.2k |
| GSA CAPITAL PARTNERS LLP 0.06% of their portfolio | 52.1k $708.0k | Reduced -118.4k |
| Mariner, LLC 0.00% of their portfolio | 48.0k $652.7k | Reduced -641 |
| Hennion & Walsh Asset Management, Inc. 0.02% of their portfolio | 47.9k $650.9k | Reduced -8.9k |
| Schonfeld Strategic Advisors LLC 0.00% of their portfolio | 43.6k $593.0k | Reduced -602.8k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 42.9k $583.4k | Unchanged |
| TD Asset Management Inc 0.00% of their portfolio | 41.0k $556.7k | New |
| CITIGROUP INC 0.00% of their portfolio | 38.1k $517.5k | Added +7.0k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 32.0k $434.9k | Reduced -6.0k |
| Monashee Investment Management LLC 0.20% of their portfolio | 30.0k $407.6k | New |
| Quadrature Capital Ltd 0.00% of their portfolio | 28.3k $384.1k | Reduced -1.1k |
| GUGGENHEIM CAPITAL LLC 0.00% of their portfolio | 24.9k $338.4k | Reduced -10.9k |
| Campbell & CO Investment Adviser LLC 0.03% of their portfolio | 24.5k $332.7k | New |