🕵️ Amylyx Pharmaceuticals, Inc. ($AMLX)
SEC insider & ownership activity, last 12 months · CIK 1658551 · every row links its SEC filing
Over the last 12 months insiders sold $10.6M against $152K of open-market buying. Justin B. Klee sold $4.0M (Sep–Sep). BlackRock, Inc. added 5.5% → 7.1%. No red-flag 8-Ks in the window.
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Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
1 buyer, $152K (2 lots) · 5 sellers, $10.6M (37 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Justin B. Klee | 0 | – | 9 | $4.0M | Sep 10, 2026 |
| Joshua B. Cohen | 0 | – | 9 | $4.0M | Sep 10, 2026 |
| Mazzariello Gina | 0 | – | 8 | $1.2M | Sep 10, 2026 |
| James M. Frates | 0 | – | 6 | $708K | Sep 10, 2026 |
| Camille L. Bedrosian | 0 | – | 5 | $689K | Sep 10, 2026 |
| Firestone Karen | 2 | $152K | 0 | – | May 21, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| FMR LLC | 15.0% | 13G | Feb 5, 2026 | filing ↗ | |
| Abigail P. Johnson | 15.0% | 13G | Feb 5, 2026 | filing ↗ | |
| Perceptive Advisors LLC | 7.5% | 13G | May 15, 2026 | filing ↗ | |
| Joseph Edelman | 7.5% | 13G | May 15, 2026 | filing ↗ | |
| Perceptive Life Sciences Master Fund, Ltd. | 7.5% | 13G | May 15, 2026 | filing ↗ | |
| BlackRock, Inc. | 7.1% | 13G | Jan 21, 2026 | filing ↗ | |
| TCG Crossover GP II, LLC | 5.7% | 13G | Feb 17, 2026 | filing ↗ | |
| TCG Crossover Fund II, L.P. | 5.7% | 13G | Feb 17, 2026 | filing ↗ | |
| Chen Yu | 5.7% | 13G | Feb 17, 2026 | filing ↗ | |
| Commodore Capital LP | 5.1% | 13G | Nov 17, 2025 | filing ↗ | |
| Commodore Capital Master LP | 5.1% | 13G | Nov 17, 2025 | filing ↗ | |
| Robert Egen Atkinson | 5.1% | 13G | Nov 17, 2025 | filing ↗ | |
| Michael Kramarz | 5.1% | 13G | Nov 17, 2025 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Gina Mazzariello | $536K | Jul 9, 2026 | filing ↗ |
| Mazzariello Gina | $99K | Mar 2, 2026 | filing ↗ |
| Joshua B. Cohen | $424K | Mar 2, 2026 | filing ↗ |
| Justin B. Klee | $424K | Mar 2, 2026 | filing ↗ |
| Camille L. Bedrosian | $94K | Mar 2, 2026 | filing ↗ |
| James M. Frates | $115K | Mar 2, 2026 | filing ↗ |
| Mazzariello Gina | $48K | Feb 23, 2026 | filing ↗ |
| Joshua B. Cohen | $228K | Feb 2, 2026 | filing ↗ |
| Justin B. Klee | $228K | Feb 2, 2026 | filing ↗ |
| Mazzariello Gina | $51K | Feb 2, 2026 | filing ↗ |
| James M. Frates | $52K | Feb 2, 2026 | filing ↗ |
| Justin Klee | $27K | Jan 16, 2026 | filing ↗ |
| Joshua Cohen | $27K | Jan 16, 2026 | filing ↗ |
| Joshua Cohen | $1.9M | Jan 15, 2026 | filing ↗ |
| Justin Klee | $1.9M | Jan 15, 2026 | filing ↗ |
| James M. Frates | $37K | Jan 6, 2026 | filing ↗ |
| Justin B. Klee | $86K | Jan 6, 2026 | filing ↗ |
| Joshua B. Cohen | $86K | Jan 6, 2026 | filing ↗ |
| Camille L. Bedrosian | $94K | Dec 1, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Material agreement (1.01) | Sep 1, 2026 | filing ↗ |
| Material agreement (1.01) | Aug 19, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 19, 2026 | filing ↗ |
| Other events (8.01) | Aug 18, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 18, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Aug 18, 2026 | filing ↗ |
| Other events (8.01) | Aug 18, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 18, 2026 | filing ↗ |
| Earnings (2.02) | Aug 6, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 6, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 4, 2026 | filing ↗ |
| Earnings (2.02) | May 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 7, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Mar 24, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 24, 2026 | filing ↗ |
| Earnings (2.02) | Mar 3, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 3, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 8, 2026 | filing ↗ |
| Other events (8.01) | Jan 8, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 8, 2026 | filing ↗ |
| Earnings (2.02) | Nov 6, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 6, 2025 | filing ↗ |