Amylyx Pharmaceuticals, Inc. (AMLX) shareholders
AMLXNasdaqPharmaceutical PreparationsFiscal year ends December 31
$30.29+0.43 (+1.44%)
Close on Nov 13, 2026Market cap $3.38BP/E –Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
115M of 111M shares
Institutional holders
207
51 new, 13 sold out
Net institutional buying
6M
In Q2 2026
Insider trades, 12 months
2 buys · 39 sales
Net sold $17.16M
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Abigail P. Johnson Joint filing with FMR LLC (15.00%) | 16,468,419 | 15.00% | 13G (passive) amendment | Dec 31, 2025 |
| Perceptive Life Sciences Master Fund, Ltd. Joint filing with Perceptive Advisors LLC (7.50%), Joseph Edelman (7.50%) | 8,284,882 | 7.50% | 13G (passive) amendment | Mar 31, 2026 |
| Perceptive Advisors LLC Joint filing with Joseph Edelman (8.80%), Perceptive Life Sciences Master Fund, Ltd. (8.80%) | 7,874,348 | 8.80% | 13G (passive) amendment | Mar 31, 2025 |
| BlackRock, Inc. | 7,783,648 | 7.10% | 13G (passive) amendment | Dec 31, 2025 |
| Joseph Edelman Joint filing with Perceptive Advisors LLC (7.90%), Perceptive Life Sciences Master Fund, Ltd. (7.90%) | 6,774,348 | 7.90% | 13G (passive) amendment | Dec 31, 2024 |
| Chen Yu Joint filing with TCG Crossover GP II, LLC (5.70%), TCG Crossover Fund II, L.P. (5.70%) | 6,243,812 | 5.70% | 13G (passive) amendment | Dec 31, 2025 |
| Robert Atchinson Joint filing with Adage Capital Management, L.P. (6.43%), Phillip Gross (6.43%) | 5,697,605 | 6.43% | 13G (passive) | Mar 31, 2025 |
| Robert Egen Atkinson Joint filing with Commodore Capital LP (5.10%), Commodore Capital Master LP (5.10%) and 1 more | 5,650,000 | 5.10% | 13G (passive) | Nov 10, 2025 |
| Point72 Asset Management, L.P. Joint filing with Point72 Capital Advisors, Inc. (5.60%), Steven A. Cohen (5.60%) | 4,820,333 | 5.60% | 13G (passive) | Jan 13, 2025 |
| Steven A. Cohen Joint filing with Point72 Asset Management, L.P. (5.30%), Point72 Capital Advisors, Inc. (5.30%) | 4,717,709 | 5.30% | 13G (passive) | Jun 24, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of AMLX | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| FMR LLC | 16,727,909 | 15.01% | $300.43M | +97,368 | 0.01% |
| BlackRock, Inc. | 8,827,085 | 7.92% | $158.53M | −1,751 | 0.00% |
| Perceptive Advisors LLC | 8,334,882 | 7.48% | $149.69M | +50,000 | 2.25% |
| TCG Crossover Management, LLC | 6,243,812 | 5.60% | $112.14M | – | 2.70% |
| Commodore Capital LP | 5,650,000 | 5.07% | $101.47M | – | 6.04% |
| Jupiter Topco LLC | 5,236,102 | 4.70% | $94.01M | New | 0.04% |
| Saturn V Capital Management LP | 4,624,101 | 4.15% | $83.05M | +274,216 | 11.91% |
| Vanguard Capital Management LLC | 4,224,224 | 3.79% | $75.87M | +82,649 | 0.00% |
| Morgan Stanley | 3,130,808 | 2.81% | $56.23M | +955,261 | 0.00% |
| Driehaus Capital Management LLC | 3,036,970 | 2.73% | $54.54M | +49,823 | 0.32% |
| First Light Asset Management, LLC | 3,023,256 | 2.71% | $54.30M | −167,389 | 3.30% |
| Franklin Resources Inc | 2,950,225 | 2.65% | $52.99M | +688,656 | 0.01% |
| Goldman Sachs Group Inc | 2,858,239 | 2.57% | $51.33M | +232,248 | 0.00% |
| State Street Corp | 2,603,337 | 2.34% | $46.76M | +240,176 | 0.00% |
| Geode Capital Management, LLC | 2,335,315 | 2.10% | $41.95M | +124,383 | 0.00% |
| Adage Capital Partners Gp, L.L.C. | 1,900,000 | 1.71% | $34.12M | −1,660,764 | 0.05% |
| JPMorgan Chase & Co | 1,863,650 | 1.67% | $34.92M | +1,703,987 | 0.00% |
| Siren, L.L.C. | 1,480,586 | 1.33% | $26.59M | +250,586 | 0.54% |
| Eventide Asset Management, LLC | 1,327,536 | 1.19% | $23.84M | −186,422 | 0.32% |
| 683 Capital Management, LLC | 1,279,512 | 1.15% | $22.98M | −250,488 | 1.13% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 207 | 115M | 100.0% | 51 / 72 | 59 / 13 | 17M | 11M |
| Q1 2026 | 171 | 115M | 100.0% | 28 / 63 | 53 / 36 | 16M | 7M |
| Q4 2025 | 180 | 112M | 100.0% | 40 / 71 | 46 / 27 | 21M | 21M |
| Q3 2025 | 169 | 112M | 100.0% | 57 / 45 | 48 / 19 | 45M | 15M |
| Q2 2025 | 131 | 82M | 73.3% | 31 / 37 | 37 / 36 | 22M | 14M |
| Q1 2025 | 136 | 74M | 66.3% | 32 / 50 | 31 / 16 | 29M | 5M |
| Q4 2024 | 122 | 50M | 44.9% | 33 / 35 | 40 / 20 | 15M | 8M |
| Q3 2024 | 110 | 44M | 39.1% | 23 / 32 | 35 / 31 | 19M | 16M |
| Q2 2024 | 119 | 44M | 39.2% | 32 / 29 | 44 / 53 | 13M | 23M |
| Q1 2024 | 143 | 54M | 48.5% | 25 / 57 | 47 / 60 | 18M | 28M |
| Q4 2023 | 178 | 64M | 57.3% | 37 / 79 | 45 / 28 | 23M | 18M |
| Q3 2023 | 170 | 60M | 53.5% | 34 / 68 | 48 / 16 | 16M | 11M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
188 funds held AMLX in Q2 2026, 32% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of AMLX | Value | % of fund | As of |
|---|---|---|---|---|---|
| Vanguard Total Stock Market Index Fund | 3,154,723 | 2.83% | $56.66M | 0.00% | Jun 30, 2026 |
| Fidelity Advisor Biotechnology Fund | 2,433,200 | 2.18% | $49.42M | 2.25% | Jul 31, 2026 |
| iShares Russell 2000 ETF | 2,360,386 | 2.12% | $42.39M | 0.05% | Jun 30, 2026 |
| Fidelity Small Cap Growth Fund | 2,115,961 | 1.90% | $42.98M | 0.49% | Jul 31, 2026 |
| Select Health Care Portfolio | 1,420,000 | 1.27% | $20.38M | 0.35% | May 31, 2026 |
| Eventide Healthcare & Life Sciences Fund | 1,324,994 | 1.19% | $23.80M | 1.33% | Jun 30, 2026 |
| Fidelity Stock Selector Small Cap Fund | 1,257,800 | 1.13% | $25.55M | 0.35% | Jul 31, 2026 |
| Strategic Advisers Fidelity U.S. Total Stock Fund | 1,138,109 | 1.02% | $16.33M | 0.01% | May 31, 2026 |
| Select Biotechnology Portfolio | 1,097,175 | 0.98% | $15.74M | 0.30% | May 31, 2026 |
| Fidelity Small Cap Growth K6 Fund | 1,053,389 | 0.95% | $21.39M | 0.47% | Jul 31, 2026 |
| Fidelity Small Cap Index Fund | 1,007,047 | 0.90% | $20.45M | 0.06% | Jul 31, 2026 |
| Fidelity Series Small Cap Opportunities Fund | 1,006,427 | 0.90% | $20.44M | 0.43% | Jul 31, 2026 |
| Vanguard Extended Market Index Fund | 963,188 | 0.86% | $17.30M | 0.02% | Jun 30, 2026 |
| Fidelity Balanced Fund | 879,837 | 0.79% | $12.63M | 0.02% | May 31, 2026 |
| iShares Russell 2000 Growth ETF | 848,854 | 0.76% | $15.25M | 0.10% | Jun 30, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| Joshua B. Cohen | Co-Chief Executive Officer, Director | 3,513,123 | 3.15% | Nov 12, 2026 |
| Justin B. Klee | Co-Chief Executive Officer, Director | 3,513,056 | 3.15% | Nov 12, 2026 |
| James M. Frates | Chief Financial Officer | 273,625 | 0.25% | Nov 12, 2026 |
| Gina Mazzariello | Chief Legal Officer | 190,838 | 0.17% | Sep 14, 2026 |
| Camille L. Bedrosian | Chief Medical Officer | 278,064 | 0.25% | Sep 14, 2026 |
| George M. Milne Jr | Director | 782,881 | 0.70% | Oct 7, 2026 |
| Karen Firestone | Director | 116,900 | 0.10% | Sep 2, 2026 |
| Bernhardt G. Zeiher | Director | 10,000 | 0.01% | Jun 8, 2026 |
| Daphne Quimi | Director | 5,000 | 0.00% | Jun 8, 2026 |
| Paul R. Fonteyne | Director | 3,947 | 0.00% | Jun 8, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| James M. Frates Chief Financial Officer | Nov 10, 2026 | Sale(10b5-1 plan) | −7,200 | $30.97 | $222.98K | 233,625 |
| James M. Frates Chief Financial Officer | Nov 10, 2026 | Sale(10b5-1 plan) | −12,800 | $30.32 | $388.11K | 240,825 |
| James M. Frates Chief Financial Officer | Nov 10, 2026 | Option exercise | +20,000 | $6.88 | $137.60K | 253,625 |
| James M. Frates Chief Financial Officer | Nov 9, 2026 | Sale(10b5-1 plan) | −12,300 | $30.11 | $370.36K | 233,625 |
| James M. Frates Chief Financial Officer | Nov 9, 2026 | Sale(10b5-1 plan) | −7,700 | $29.39 | $226.29K | 245,925 |
| James M. Frates Chief Financial Officer | Nov 9, 2026 | Option exercise | +20,000 | $6.88 | $137.60K | 253,625 |
| Justin B. Klee Co-Chief Executive Officer, Director | Nov 9, 2026 | Sale(10b5-1 plan) | −62,517 | $30.11 | $1.88M | 3,513,056 |
| Justin B. Klee Co-Chief Executive Officer, Director | Nov 9, 2026 | Sale(10b5-1 plan) | −37,483 | $29.39 | $1.10M | 3,575,573 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Nov 9, 2026 | Sale(10b5-1 plan) | −61,895 | $30.11 | $1.86M | 3,513,123 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Nov 9, 2026 | Sale(10b5-1 plan) | −38,105 | $29.39 | $1.12M | 3,575,018 |
| George M. Milne Jr Director | Oct 5, 2026 | Sale(10b5-1 plan) | −30,000 | $27.70 | $830.90K | 782,881 |
| Camille L. Bedrosian Chief Medical Officer | Sep 10, 2026 | Sale | −2,081 | $33.09 | $68.86K | 278,064 |
| Camille L. Bedrosian Chief Medical Officer | Sep 10, 2026 | Sale | −7,947 | $32.21 | $255.97K | 280,145 |
| Justin B. Klee Co-Chief Executive Officer, Director | Sep 10, 2026 | Sale | −29,025 | $32.13 | $932.57K | 3,614,495 |
| Justin B. Klee Co-Chief Executive Officer, Director | Sep 10, 2026 | Sale | −1,439 | $33.16 | $47.72K | 3,613,056 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Sep 10, 2026 | Sale | −29,545 | $32.16 | $950.17K | 3,614,042 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Sep 10, 2026 | Sale | −919 | $33.15 | $30.46K | 3,613,123 |
| James M. Frates Chief Financial Officer | Sep 10, 2026 | Sale | −1,042 | $33.23 | $34.63K | 233,625 |
| James M. Frates Chief Financial Officer | Sep 10, 2026 | Sale | −9,768 | $32.27 | $315.21K | 234,667 |
| Gina Mazzariello Chief Legal Officer | Sep 10, 2026 | Sale | −11 | $33.34 | $367 | 190,838 |
| Gina Mazzariello Chief Legal Officer | Sep 10, 2026 | Sale | −9,525 | $32.46 | $309.18K | 190,849 |
| Karen Firestone Director | Aug 31, 2026 | Option exercise | +25,000 | $5.05 | $126.25K | 116,900 |
| Karen Firestone Director | Aug 31, 2026 | Option exercise | +25,000 | $1.76 | $44.00K | 91,900 |
| James M. Frates Chief Financial Officer | Aug 18, 2026 | Award | +22,807 | – | – | 244,435 |
| Camille L. Bedrosian Chief Medical Officer | Aug 18, 2026 | Award | +22,807 | – | – | 288,092 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Aug 18, 2026 | Award | +60,039 | – | – | 3,643,587 |
| Gina Mazzariello Chief Legal Officer | Aug 18, 2026 | Award | +21,284 | – | – | 200,374 |
| Justin B. Klee Co-Chief Executive Officer, Director | Aug 18, 2026 | Award | +60,039 | – | – | 3,643,520 |
| Gina Mazzariello Chief Legal Officer | Jul 10, 2026 | Sale(10b5-1 plan) | −15,000 | $17.61 | $264.15K | 179,090 |
| Gina Mazzariello Chief Legal Officer | Jul 9, 2026 | Sale(10b5-1 plan) | −15,000 | $18.32 | $274.80K | 194,090 |
| Karen Firestone Director | May 21, 2026 | Buy | +3,800 | $13.51 | $51.34K | 66,900 |
| James M. Frates Chief Financial Officer | Mar 5, 2026 | Award | +95,990 | – | – | 261,628 |
| Justin B. Klee Co-Chief Executive Officer, Director | Mar 5, 2026 | Award | +248,865 | – | – | 3,583,481 |
| Camille L. Bedrosian Chief Medical Officer | Mar 5, 2026 | Award | +95,990 | – | – | 265,285 |
| Gina Mazzariello Chief Legal Officer | Mar 5, 2026 | Award | +74,660 | – | – | 209,090 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Mar 5, 2026 | Award | +248,865 | – | – | 3,583,548 |
| Gina Mazzariello Chief Legal Officer | Mar 2, 2026 | Sale | −6,844 | $14.52 | $99.37K | 134,430 |
| Justin B. Klee Co-Chief Executive Officer, Director | Mar 2, 2026 | Sale | −29,282 | $14.47 | $423.71K | 3,334,616 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Mar 2, 2026 | Sale | −29,282 | $14.48 | $424.00K | 3,334,683 |
| James M. Frates Chief Financial Officer | Mar 2, 2026 | Sale | −7,909 | $14.52 | $114.84K | 165,638 |
| Camille L. Bedrosian Chief Medical Officer | Mar 2, 2026 | Sale | −6,461 | $14.58 | $94.20K | 169,295 |
| Gina Mazzariello Chief Legal Officer | Feb 23, 2026 | Sale | −3,419 | $14.14 | $48.34K | 141,274 |
| Gina Mazzariello Chief Legal Officer | Feb 2, 2026 | Sale | −3,448 | $14.65 | $50.51K | 144,693 |
| Justin B. Klee Co-Chief Executive Officer, Director | Feb 2, 2026 | Sale | −15,500 | $14.69 | $227.70K | 3,363,898 |
| James M. Frates Chief Financial Officer | Feb 2, 2026 | Sale | −3,557 | $14.65 | $52.11K | 173,547 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Feb 2, 2026 | Sale | −15,500 | $14.68 | $227.54K | 3,363,965 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Jan 16, 2026 | Sale | −1,974 | $13.83 | $27.30K | 3,379,465 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Jan 16, 2026 | Option exercise | +2,818 | $7.57 | $21.33K | 3,381,439 |
| Justin B. Klee Co-Chief Executive Officer, Director | Jan 16, 2026 | Sale | −1,995 | $13.89 | $27.71K | 3,379,398 |
| Justin B. Klee Co-Chief Executive Officer, Director | Jan 16, 2026 | Option exercise | +2,847 | $7.57 | $21.55K | 3,381,393 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Jan 15, 2026 | Sale | −136,193 | $13.59 | $1.85M | 3,378,621 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Jan 15, 2026 | Option exercise | +197,182 | $7.57 | $1.49M | 3,514,814 |
| Justin B. Klee Co-Chief Executive Officer, Director | Jan 15, 2026 | Sale | −136,193 | $13.58 | $1.85M | 3,378,546 |
| Justin B. Klee Co-Chief Executive Officer, Director | Jan 15, 2026 | Option exercise | +197,153 | $7.57 | $1.49M | 3,514,739 |
| George M. Milne Jr Director | Jan 12, 2026 | Gift | −17,780 | – | – | 812,881 |
| James M. Frates Chief Financial Officer | Jan 6, 2026 | Sale | −3,326 | $11.11 | $36.95K | 177,104 |
| Joshua B. Cohen Co-Chief Executive Officer, Director | Jan 6, 2026 | Sale | −7,715 | $11.09 | $85.56K | 3,317,632 |
| Justin B. Klee Co-Chief Executive Officer, Director | Jan 6, 2026 | Sale | −7,715 | $11.09 | $85.56K | 3,317,586 |
| Karen Firestone Director | Dec 23, 2025 | Buy | +8,100 | $12.45 | $100.85K | 63,100 |
| Camille L. Bedrosian Chief Medical Officer | Dec 1, 2025 | Sale | −6,580 | $14.35 | $94.42K | 175,756 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
12.48%
13M shares short
Days to cover
10.5
At 1M shares a day
Change since last report
-3.2%
From 13M shares
Short volume, 20 days
50.5%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of Amylyx Pharmaceuticals's stock actually held short. Settlement fails (shares not delivered on time) peaked at 63,699 shares on Aug 19, 2026 over the last 90 days.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Joshua B. Cohen Director, Officer | Nov 9, 2026 | 100,000 | $2.95M | Nov 9, 2026 | Founders Shares |
| James M. Frates Officer | Nov 9, 2026 | 40,000 | $1.18M | Nov 9, 2026 | Exercise of Stock Options |
| Justin B. Klee Director, Officer | Nov 9, 2026 | 100,000 | $2.95M | Nov 9, 2026 | Founders Shares |
| George M. Milne Jr Director | Oct 5, 2026 | 100,000 | $2.78M | Oct 5, 2026 | Private Acquisition from Issuer or an Affiliate |
| Justin B. Klee Officer, Director | Sep 11, 2026 | 30,464 | $980.26K | Sep 10, 2026 | Vesting of Performance-based Restricted Stock Units |
| James M. Frates Officer | Sep 11, 2026 | 10,810 | $349.82K | Sep 10, 2026 | Vesting of Performance-based Restricted Stock Units |
| Camille L. Bedrosian Officer | Sep 11, 2026 | 10,028 | $324.87K | Sep 10, 2026 | Vesting of Performance-based Restricted Stock Units |
| Gina Mazzariello Officer | Sep 11, 2026 | 9,536 | $309.51K | Sep 10, 2026 | Vesting of Performance-based Restricted Stock Units |
| Joshua B. Cohen Officer, Director | Sep 11, 2026 | 30,464 | $980.50K | Sep 10, 2026 | Vesting of Performance-based Restricted Stock Units |
| Gina Mazzariello Officer | Jul 9, 2026 | 30,000 | $536.40K | Jul 9, 2026 | Restricted Stock Units |
| Justin B. Klee Officer, Director | Mar 2, 2026 | 29,282 | $423.76K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| Camille L. Bedrosian Officer | Mar 2, 2026 | 6,461 | $94.21K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| James M. Frates Officer | Mar 2, 2026 | 7,909 | $114.85K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| Gina Mazzariello Officer | Mar 2, 2026 | 6,844 | $99.38K | Mar 2, 2026 | Vesting of Restricted Stock Units |
| Joshua B. Cohen Officer, Director | Mar 2, 2026 | 29,282 | $424.12K | Mar 2, 2026 | Vesting of Restricted Stock Units |
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