Comparable stake leader
FMR LLC
SEC ownership of Amylyx Pharmaceuticals, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001658551.
Disclosed value leader
FMR LLC
Comparable rows
50/50
Latest evidence
31 Aug 2026
- Public ticker
- AMLX on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
FMR LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
FMR LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
31 Aug 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001658551
- Issuer location
- Cambridge, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Amylyx Pharmaceuticals, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
FMR LLC
Disclosed value leader
FMR LLC
Comparable rows
50/50
Latest evidence
31 Aug 2026
13F
13D/G
3/4/5
Lead comparable stake: 15%
13D/G row: FMR LLC
Showing 1-8 of 50 holder rows.
Quick read
FMR LLC leads the comparable SEC ownership view at 15%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens FMR LLC's linked filing trail.
Comparable ownership
Top 5
FMR LLC
15%
PERCEPTIVE ADVISORS LLC
7.5%
BlackRock, Inc.
7.1%
TCG Crossover GP II, LLC
5.7%
Commodore Capital LP
5.1%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FMR LLC |
13F
13D/G
Company
|
15%
from 13D/G
|
$300,433,246
16,727,909 shares
|
— | 30 Jun 2026 |
| PERCEPTIVE ADVISORS LLC |
13F
13D/G
Company
|
7.5%
from 13D/G
|
$149,694,481
8,334,882 shares
|
— | 30 Jun 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
7.1%
from 13D/G
|
$158,534,442
8,827,085 shares
|
— | 30 Jun 2026 |
| TCG Crossover GP II, LLC |
13D/G
|
5.7%
|
$74,863,306
6,243,812 shares
|
$0 | 31 Dec 2025 |
| Commodore Capital LP |
13F
13D/G
Company
|
5.1%
from 13D/G
|
$101,474,000
5,650,000 shares
|
— | 30 Jun 2026 |
| Point72 Asset Management, L.P. |
13D/G
|
2.6%
|
$38,074,233
2,801,636 shares
|
-$26,039,432 | 30 Sep 2025 |
| Panacea Innovation Ltd |
13D/G
Panacea Venture Healthcare Fund II, L.P.
|
2.6%
|
$11,792,000
2,200,000 shares
|
$0 | 31 Dec 2024 |
| Adage Capital Management, L.P. |
13D/G
|
2.5%
|
$33,296,889
2,777,055 shares
|
-$48,436,878 | 31 Dec 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$7,526,655.
Buys
$152,183
Insiders: 1
Sells
$7,678,838
Insiders: 5
Net
-$7,526,655
Shares: -532,326
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 11,900
Shares: 544,226
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 30,000 | $0 | $538,868 | -$538,868 |
| 3-6 | 3,800 | 0 | $51,338 | $0 | +$51,338 |
| 6-9 | 8,100 | 416,313 | $100,845 | $5,726,294 | -$5,625,449 |
| 9-12 | 0 | 97,913 | $0 | $1,413,677 | -$1,413,677 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-17 of 17 reporting-owner rows connected to Amylyx Pharmaceuticals, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
17
Largest Forms 3/4/5 holder
ALS Invest 1 B.V.
Net 12M change
-$7,526,654
Latest report
31 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| ALS Invest 1 B.V. | 10%+ Owner | $96,258,721 | Mixed | 06 Jul 2022 | ||
| Morningside Venture Investments Ltd | 10%+ Owner | $81,596,447 | Mixed | 15 Aug 2023 | ||
| Joshua B. Cohen | Co-Chief Executive Officer, Director | $65,438,822 | -$3,044,872 | -4.4% | Median | 18 Aug 2026 |
| Justin B. Klee | Co-Chief Executive Officer, Director | $65,437,619 | -$3,045,489 | -4.4% | Median | 18 Aug 2026 |
| DRAGSA 96 LLC | 10%+ Owner | $37,554,630 | Mixed | 11 Jan 2022 | ||
| VIKING GLOBAL INVESTORS LP | 10%+ Owner | $30,222,333 | Mixed | 08 Sep 2022 | ||
| George M. Milne Jr. | Director | $9,819,602 | Mixed | 04 Jun 2026 | ||
| Margaret Olinger | Chief Commercial Officer | $5,178,792 | Mixed | 27 Dec 2023 | ||
| Camille L. Bedrosian | Chief Medical Officer | $5,174,132 | -$364,141 | -6.6% | Median | 18 Aug 2026 |
| James M. Frates | Chief Financial Officer | $5,108,452 | -$358,552 | -6.6% | Median | 18 Aug 2026 |
| Gina Mazzariello | Chief Legal Officer | $3,598,717 | -$865,783 | -19% | Median | 18 Aug 2026 |
| Patrick D. Yeramian | Chief Medical Officer | $3,357,139 | Filing P/S | 09 Jan 2024 | ||
| Karen Firestone | Director | $2,099,524 | +$152,183 | +7.8% | Median | 31 Aug 2026 |
| Bernhardt G. Zeiher | Director | $37,005 | Filing P/S | 04 Jun 2026 | ||
| Isaac Cheng | Director | Mixed | 09 Jun 2022 | |||
| Daphne Quimi | Director | Mixed | 04 Jun 2026 | |||
| Paul R. Fonteyne | Director | Mixed | 04 Jun 2026 |
Recent insider transactions for Amylyx Pharmaceuticals, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Karen Firestone | AMLX | Common Stock | Options Exercise | 74.7% | 50,000 | 116,900 | 31 Aug 2026 | Direct | ||
| Karen Firestone | AMLX | Stock Option (right to buy) | Options Exercise | -100% | -25,000 | 0 | 31 Aug 2026 | Direct | ||
| James M. Frates | AMLX | Common Stock | Award | 10.3% | 22,807 | 244,435 | 18 Aug 2026 | Direct | ||
| Justin B. Klee | AMLX | Common Stock | Award | 1.68% | 60,039 | 3,643,520 | 18 Aug 2026 | Direct | ||
| Gina Mazzariello | AMLX | Common Stock | Award | 11.9% | 21,284 | 200,374 | 18 Aug 2026 | Direct | ||
| Camille L. Bedrosian | AMLX | Common Stock | Award | 8.6% | 22,807 | 288,092 | 18 Aug 2026 | Direct | ||
| Joshua B. Cohen | AMLX | Common Stock | Award | 1.68% | 60,039 | 3,643,587 | 18 Aug 2026 | Direct | ||
| Gina Mazzariello | AMLX | Common Stock | Sale | -7.73% | $264,122 | $17.61 | -15,000 | 179,090 | 10 Jul 2026 | Direct |
| Gina Mazzariello | AMLX | Common Stock | Sale | -7.17% | $274,746 | $18.32 | -15,000 | 194,090 | 09 Jul 2026 | Direct |
| Bernhardt G. Zeiher | AMLX | Stock Option (right to buy) | Award | 24,372 | 24,372 | 04 Jun 2026 | Direct | |||
| Karen Firestone | AMLX | Stock Option (right to buy) | Award | 24,372 | 24,372 | 04 Jun 2026 | Direct | |||
| Daphne Quimi | AMLX | Stock Option (right to buy) | Award | 24,372 | 24,372 | 04 Jun 2026 | Direct | |||
| George M. Milne Jr. | AMLX | Stock Option (right to buy) | Award | 24,372 | 24,372 | 04 Jun 2026 | Direct | |||
| Paul R. Fonteyne | AMLX | Stock Option (right to buy) | Award | 24,372 | 24,372 | 04 Jun 2026 | Direct | |||
| Karen Firestone | AMLX | Common Stock | Purchase | 6.02% | $51,338 | $13.51 | 3,800 | 66,900 | 21 May 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Award | 7.46% | 248,865 | 3,583,548 | 05 Mar 2026 | Direct | ||
| Joshua B. Cohen | AMLX | Stock Option (Right to Buy) | Award | 373,295 | 373,295 | 05 Mar 2026 | Direct | |||
| Gina Mazzariello | AMLX | Common Stock | Award | 55.5% | 74,660 | 209,090 | 05 Mar 2026 | Direct | ||
| Gina Mazzariello | AMLX | Stock Option (Right to Buy) | Award | 111,990 | 111,990 | 05 Mar 2026 | Direct | |||
| James M. Frates | AMLX | Common Stock | Award | 58% | 95,990 | 261,628 | 05 Mar 2026 | Direct | ||
| James M. Frates | AMLX | Stock Option (right to buy) | Award | 143,985 | 143,985 | 05 Mar 2026 | Direct | |||
| Justin B. Klee | AMLX | Common Stock | Award | 7.46% | 248,865 | 3,583,481 | 05 Mar 2026 | Direct | ||
| Justin B. Klee | AMLX | Stock Option (Right to Buy) | Award | 373,295 | 373,295 | 05 Mar 2026 | Direct | |||
| Camille L. Bedrosian | AMLX | Common Stock | Award | 56.7% | 95,990 | 265,285 | 05 Mar 2026 | Direct | ||
| Camille L. Bedrosian | AMLX | Stock Option (Right to Buy) | Award | 143,985 | 143,985 | 05 Mar 2026 | Direct | |||
| Justin B. Klee | AMLX | Common Stock | Sale | -0.87% | $423,760 | $14.47 | -29,282 | 3,334,616 | 02 Mar 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Sale | -0.87% | $424,120 | $14.48 | -29,282 | 3,334,683 | 02 Mar 2026 | Direct |
| Camille L. Bedrosian | AMLX | Common Stock | Sale | -3.68% | $94,205 | $14.58 | -6,461 | 169,295 | 02 Mar 2026 | Direct |
| James M. Frates | AMLX | Common Stock | Sale | -4.56% | $114,851 | $14.52 | -7,909 | 165,638 | 02 Mar 2026 | Direct |
| Gina Mazzariello | AMLX | Common Stock | Sale | -4.84% | $99,378 | $14.52 | -6,844 | 134,430 | 02 Mar 2026 | Direct |
| Gina Mazzariello | AMLX | Common Stock | Sale | -2.36% | $48,352 | $14.14 | -3,419 | 141,274 | 23 Feb 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Sale | -0.46% | $227,593 | $14.68 | -15,500 | 3,363,965 | 02 Feb 2026 | Direct |
| Gina Mazzariello | AMLX | Common Stock | Sale | -2.33% | $50,516 | $14.65 | -3,448 | 144,693 | 02 Feb 2026 | Direct |
| Justin B. Klee | AMLX | Common Stock | Sale | -0.46% | $227,618 | $14.68 | -15,500 | 3,363,898 | 02 Feb 2026 | Direct |
| James M. Frates | AMLX | Common Stock | Sale | -2.01% | $52,097 | $14.65 | -3,557 | 173,547 | 02 Feb 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Sale | -0.06% | $27,299 | $13.83 | -1,974 | 3,379,465 | 16 Jan 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Options Exercise | 0.08% | 2,818 | 3,381,439 | 16 Jan 2026 | Direct | ||
| Joshua B. Cohen | AMLX | Stock Option (Right to Buy) | Options Exercise | -100% | -2,818 | 0 | 16 Jan 2026 | Direct | ||
| Justin B. Klee | AMLX | Common Stock | Sale | -0.06% | $27,701 | $13.89 | -1,995 | 3,379,398 | 16 Jan 2026 | Direct |
| Justin B. Klee | AMLX | Common Stock | Options Exercise | 0.08% | 2,847 | 3,381,393 | 16 Jan 2026 | Direct | ||
| Justin B. Klee | AMLX | Stock Option (Right to Buy) | Options Exercise | -100% | -2,847 | 0 | 16 Jan 2026 | Direct | ||
| Joshua B. Cohen | AMLX | Common Stock | Sale | -3.87% | $1,850,795 | $13.59 | -136,193 | 3,378,621 | 15 Jan 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Options Exercise | 5.94% | 197,182 | 3,514,814 | 15 Jan 2026 | Direct | ||
| Joshua B. Cohen | AMLX | Stock Option (Right to Buy) | Options Exercise | -98.6% | -197,182 | 2,818 | 15 Jan 2026 | Direct | ||
| Justin B. Klee | AMLX | Common Stock | Sale | -3.87% | $1,849,869 | $13.58 | -136,193 | 3,378,546 | 15 Jan 2026 | Direct |
| Justin B. Klee | AMLX | Common Stock | Options Exercise | 5.94% | 197,153 | 3,514,739 | 15 Jan 2026 | Direct | ||
| Justin B. Klee | AMLX | Stock Option (Right to Buy) | Options Exercise | -98.6% | -197,153 | 2,847 | 15 Jan 2026 | Direct | ||
| George M. Milne Jr. | AMLX | Common Stock | Gift | -2.14% | -17,780 | 812,881 | 12 Jan 2026 | Direct | ||
| James M. Frates | AMLX | Common Stock | Sale | -1.84% | $36,954 | $11.11 | -3,326 | 177,104 | 06 Jan 2026 | Direct |
| Joshua B. Cohen | AMLX | Common Stock | Sale | -0.23% | $85,596 | $11.09 | -7,715 | 3,317,632 | 06 Jan 2026 | Direct |
* marks a reported price that did not pass the local price check.