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 ($68.9k 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 ≈ $12.08. Options: 8 managers hold calls ($6.4m notional), 7 hold puts ($775.5k).
Trends to Q4 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 |
| Q4 2025 | 180 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| 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 |
| Q4 2025 | 107 | 72 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $524.4k | $605.5k | 1.15 |
| Q2 2025 | $1.5m | $102.9k | 0.07 |
| Q3 2025 | $7.3m | $2.2m | 0.29 |
| Q4 2025 | $6.4m | $775.5k | 0.12 |
Biggest buyers
| FMR LLC | Added | +5.1m |
| JANUS HENDERSON GROUP PLC | Added | +1.9m |
| BlackRock, Inc. | Added | +1.9m |
| Commodore Capital LP | Added | +1.6m |
| FRANKLIN RESOURCES INC | New | +1.2m |
| BANK OF AMERICA CORP /DE/ | Added | +906.5k |
| Driehaus Capital Management LLC | Added | +688.7k |
| GOLDMAN SACHS GROUP INC | Added | +602.6k |
| VANGUARD GROUP INC | Added | +531.2k |
| Sofinnova Investments, Inc. | New | +527.1k |
Biggest sellers
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -4.0m |
| Point72 Asset Management, L.P. | Reduced | -2.5m |
| Almitas Capital LLC | Reduced | -2.1m |
| Paradigm Biocapital Advisors LP | Sold out | -1.9m |
| T. Rowe Price Investment Management, Inc. | Reduced | -1.2m |
| UBS Group AG | Reduced | -861.1k |
| ORBIMED ADVISORS LLC | Sold out | -750.6k |
| PERCEPTIVE ADVISORS LLC | Reduced | -667.5k |
| Invesco Ltd. | Reduced | -634.7k |
| Balyasny Asset Management L.P. | Reduced | -617.6k |
Biggest calls
| GROUP ONE TRADING LLC | Added | $2.4m198.5k shares |
| CITADEL ADVISORS LLC | Added | $1.4m111.9k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.3m108.3k shares |
| Walleye Capital LLC | Added | $381.7k31.6k shares |
| JANE STREET GROUP, LLC | Reduced | $375.7k31.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $340.7k28.2k shares |
| Belvedere Trading LLC | New | $143.8k11.9k shares |
| Walleye Trading LLC | New | $90.6k7.5k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $262.1k21.7k shares |
| Walleye Trading LLC | New | $145.0k12.0k shares |
| JANE STREET GROUP, LLC | New | $122.0k10.1k shares |
| Walleye Capital LLC | Added | $107.5k8.9k shares |
| GROUP ONE TRADING LLC | Added | $76.1k6.3k shares |
| SIMPLEX TRADING, LLC | Reduced | $32.6k2.7k shares |
| Belvedere Trading LLC | New | $30.2k2.5k 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 Q4 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 |
|---|---|---|---|---|---|
| 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 |
| Q4 2025 | 1 | $100.8k | 1 | $94.4k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-12-23 | Firestone Karen Director | Bought | $100.8k8.1k shares |
| 2025-12-01 | Bedrosian Camille L Chief Medical Officer | Sold | $94.4k6.6k 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, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| FMR LLC 0.01% of their portfolio | 16.5m $199.5m | Added +5.1m |
| BlackRock, Inc. 0.00% of their portfolio | 9.1m $109.4m | Added +1.9m |
| PERCEPTIVE ADVISORS LLC 1.83% of their portfolio | 8.3m $100.1m | Reduced -667.5k |
| TCG Crossover Management, LLC 2.50% of their portfolio | 6.2m $75.4m | Unchanged |
| VANGUARD GROUP INC 0.00% of their portfolio | 5.8m $70.1m | Added +531.2k |
| Commodore Capital LP 4.54% of their portfolio | 5.7m $68.3m | Added +1.6m |
| Saturn V Capital Management LP 9.97% of their portfolio | 4.5m $54.3m | Reduced -108.4k |
| JANUS HENDERSON GROUP PLC 0.02% of their portfolio | 4.5m $54.0m | Added +1.9m |
| First Light Asset Management, LLC 3.10% of their portfolio | 3.4m $40.5m | Reduced -343 |
| Driehaus Capital Management LLC 0.26% of their portfolio | 3.1m $37.6m | Added +688.7k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.05% of their portfolio | 2.8m $33.5m | Reduced -4.0m |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.6m $31.6m | Added +602.6k |
| MORGAN STANLEY 0.00% of their portfolio | 2.4m $28.5m | Added +409.5k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 2.2m $26.2m | Added +353.5k |
| Almitas Capital LLC 5.65% of their portfolio | 2.1m $25.6m | Reduced -2.1m |
| STATE STREET CORP 0.00% of their portfolio | 2.1m $25.0m | Added +448.6k |
| GREAT POINT PARTNERS LLC 6.85% of their portfolio | 1.8m $21.1m | Added +50.0k |
| 683 Capital Management, LLC 1.66% of their portfolio | 1.6m $19.9m | Reduced -110.0k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.29% of their portfolio | 1.5m $18.3m | Added +648 |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 1.3m $16.1m | Added +906.5k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 1.3m $16.1m | Reduced -32.3k |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 1.2m $14.5m | New |
| Connor, Clark & Lunn Investment Management Ltd. 0.03% of their portfolio | 1.0m $12.1m | Reduced -103.0k |
| Logos Global Management LP 0.76% of their portfolio | 950.0k $11.5m | Reduced -500.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 937.8k $11.3m | Added +115.5k |
| ADAR1 Capital Management, LLC 0.80% of their portfolio | 890.4k $10.8m | Added +24.2k |
| Balyasny Asset Management L.P. 0.02% of their portfolio | 858.7k $10.4m | Reduced -617.6k |
| Woodline Partners LP 0.04% of their portfolio | 845.4k $10.2m | Added +118 |
| Nantahala Capital Management, LLC 0.60% of their portfolio | 835.7k $10.1m | Reduced -100.0k |
| Boxer Capital Management, LLC 2.12% of their portfolio | 800.0k $9.7m | Reduced -100.0k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 771.2k $9.3m | Added +261.5k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 713.0k $8.6m | Added +67.8k |
| STEMPOINT CAPITAL LP 1.17% of their portfolio | 565.1k $6.8m | Added +288.3k |
| UBS Group AG 0.00% of their portfolio | 543.3k $6.6m | Reduced -861.1k |
| Sofinnova Investments, Inc. 0.27% of their portfolio | 527.1k $6.4m | New |
| SILVERARC CAPITAL MANAGEMENT, LLC 0.88% of their portfolio | 506.2k $6.1m | Reduced -193.8k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 502.4k $6.1m | Added +368.9k |
| Rock Springs Capital Management LP 0.31% of their portfolio | 499.8k $6.0m | Unchanged |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 457.4k $5.5m | Added +245.0k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 412.9k $5.0m | Added +245.8k |
| Cormorant Asset Management, LP 0.27% of their portfolio | 400.0k $4.8m | Reduced -100.0k |
| Parkman Healthcare Partners LLC 0.44% of their portfolio | 381.8k $4.6m | Reduced -197.4k |
| Patient Square Capital LP 0.91% of their portfolio | 350.0k $4.2m | Added +33.7k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 345.0k $4.2m | Added +110.3k |
| TWO SIGMA INVESTMENTS, LP 0.01% of their portfolio | 344.4k $4.2m | Added +246.0k |
| Point72 Asset Management, L.P. 0.01% of their portfolio | 335.0k $4.0m | Reduced -2.5m |
| ACUTA CAPITAL PARTNERS, LLC 2.73% of their portfolio | 333.3k $4.0m | Unchanged |
| TWO SIGMA ADVISERS, LP 0.01% of their portfolio | 328.4k $4.0m | Added +185.4k |
| Alpha Wave Global, LP 0.47% of their portfolio | 317.7k $3.8m | Reduced -9.6k |
| BARCLAYS PLC 0.00% of their portfolio | 295.2k $3.6m | Reduced -118.9k |
| Nuveen, LLC 0.00% of their portfolio | 283.9k $3.4m | Added +123.5k |
| Tetragon Partners GP Ltd 0.69% of their portfolio | 272.8k $3.3m | Added +14.6k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 263.2k $3.2m | New |
| ACADIAN ASSET MANAGEMENT LLC 0.01% of their portfolio | 254.3k $3.1m | Reduced -113.0k |
| HighVista Strategies LLC 0.74% of their portfolio | 238.8k $2.9m | New |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 225.8k $2.7m | Reduced -10.4k |
| SummitTX Capital, L.P. 0.08% of their portfolio | 218.4k $2.6m | Added +50.4k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 217.3k $2.6m | Added +34.4k |
| Aldebaran Capital, LLC 2.15% of their portfolio | 198.5k $2.4m | Reduced -6.0k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 192.5k $2.3m | Added +172.6k |
| XTX Topco Ltd 0.06% of their portfolio | 189.7k $2.3m | New |
| Invesco Ltd. 0.00% of their portfolio | 175.9k $2.1m | Reduced -634.7k |
| Swiss National Bank 0.00% of their portfolio | 161.7k $2.0m | New |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.01% of their portfolio | 153.4k $1.9m | New |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 146.3k $1.8m | Added +52.6k |
| Atom Investors LP 0.13% of their portfolio | 139.4k $1.7m | New |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 138.5k $1.7m | Reduced -5.2k |
| PFM Health Sciences, LP 0.16% of their portfolio | 134.5k $1.6m | Reduced -301.6k |
| Numerai GP LLC 0.16% of their portfolio | 112.6k $1.4m | Added +45.5k |
| Elmind Capital, LP 0.40% of their portfolio | 112.0k $1.4m | First filing |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 107.5k $1.3m | Added +7.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 99.3k $1.2m | Added +617 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 98.8k $1.2m | New |
| ALPS ADVISORS INC 0.01% of their portfolio | 90.2k $1.1m | New |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 84.1k $1.0m | Added +70.3k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 79.1k $955.4k | Added +74.8k |
| Campbell & CO Investment Adviser LLC 0.05% of their portfolio | 78.8k $951.5k | Added +54.3k |
| Squarepoint Ops LLC 0.00% of their portfolio | 76.6k $924.9k | New |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 73.2k $884.5k | Added +4.3k |
| Legal & General Group Plc 0.00% of their portfolio | 72.6k $877.2k | Added +5.4k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 71.5k $863.7k | Unchanged |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 68.9k $832.2k | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 66.5k $803.9k | Reduced -5.1k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 65.4k $790.5k | Added +10.0k |
| Kennondale Capital Management LLC 0.47% of their portfolio | 53.4k $645.4k | Reduced -55.2k |
| Informed Momentum Co LLC 0.07% of their portfolio | 53.3k $643.3k | Reduced -21.9k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 52.9k $638.5k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 49.7k $599.8k | Added +6.7k |
| Trexquant Investment LP 0.01% of their portfolio | 48.1k $581.2k | Reduced -174.8k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 46.5k $561.2k | Reduced -371.3k |
| Mariner, LLC 0.00% of their portfolio | 46.3k $559.9k | Reduced -1.7k |
| PSP Research LLC 0.47% of their portfolio | 44.2k $534.2k | First filing |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 41.2k $497.3k | Added +9.2k |
| CITIGROUP INC 0.00% of their portfolio | 38.0k $459.4k | Reduced -51 |
| GSA CAPITAL PARTNERS LLP 0.04% of their portfolio | 36.8k $444.0k | Reduced -15.3k |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 35.9k $433.4k | Added +34.0k |
| FOX RUN MANAGEMENT, L.L.C. 0.07% of their portfolio | 35.4k $427.7k | New |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 32.0k $386.6k | Added +12.5k |
| Persistent Asset Partners Ltd 0.18% of their portfolio | 31.1k $376.3k | Added +8.2k |
| Headlands Technologies LLC 0.03% of their portfolio | 30.5k $369.0k | New |