James M. Frates - 10 Sep 2026 Form 4 Insider Report for Amylyx Pharmaceuticals, Inc. (AMLX)

Reporting relationship: Chief Financial Officer
Issuer ticker: AMLX
Reported as of: 10 Sep 2026
Net transaction value: -$349,821
SEC form: 4
Accepted by SEC: 14 Sep 2026, 16:00:08 UTC
Prior SEC filing: 20 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/ Joshua B. Cohen, as Attorney in Fact

Key filing fact

James M. Frates filed Form 4 for Amylyx Pharmaceuticals, Inc. (AMLX) on 14 Sep 2026.

Key facts

This page summarizes James M. Frates's Form 4 filing for Amylyx Pharmaceuticals, Inc. (AMLX).
2 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 14 Sep 2026, 16:00.

Change

Previous filing in this sequence was filed on 20 Aug 2026.
Current net transaction value: -$349,821.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001235598 Primary reporting owner

FRATES JAMES M

Relationship: Chief Financial Officer
Address: C/O AMYLYX PHARMACEUTICALS, INC., 55 CAMBRIDGE PARKWAY, SUITE 6W, CAMBRIDGE
Signature: /s/ Joshua B. Cohen, as Attorney in Fact
Signature date: 14 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

AMLX transaction

Common Stock

Sale

Transaction value: $315,195
Shares: -9,768
Change %: -4%
Price: $32.27
Shares after: 234,667
Date: 10 Sep 2026
Ownership: Direct
Footnotes: F1, F2

AMLX transaction

Common Stock

Sale

Transaction value: $34,626
Shares: -1,042
Change %: -0.44%
Price: $33.23
Shares after: 233,625
Date: 10 Sep 2026
Ownership: Direct
Footnotes: F1, F3

AMLX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 100,000
Date: 10 Sep 2026
Ownership: By Trust
Footnotes: F4

AMLX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 15,459
Date: 10 Sep 2026
Ownership: By Trust
Footnotes: F5

AMLX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 11,072
Date: 10 Sep 2026
Ownership: By Trust
Footnotes: F6

AMLX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 40,000
Date: 10 Sep 2026
Ownership: By Trust
Footnotes: F7

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 7 footnotes

Footnote F1

Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of performance stock units. Such sales were automatic and not at the discretion of the Reporting Person.

Footnote F2

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $31.805 to $32.71. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

Footnote F3

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $32.84 to $33.45. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

Footnote F4

Shares held by the JAMES M. FRATES 2025 GRAT NO 1 U/A DTD 12/12/2025, for which the Reporting Person serves as trustee and is the sole annuitant. The Reporting Person disclaims beneficial ownership of such shares for purposes of Section 16 except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose.

Footnote F5

Shares held by the James M. Frates 2024 Grantor Retained Annuity Trust No. 1, for which the Reporting Person serves as trustee and is the sole annuitant. The Reporting Person disclaims beneficial ownership of such shares for purposes of Section 16 except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose.

Footnote F6

Shares held by the FRATES FAMILY 2013 IRREV TRUST, for which the Reporting Person serves as trustee. The Reporting Person disclaims beneficial ownership of such shares for purposes of Section 16 except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose.

Footnote F7

Shares held by the JAMES M. FRATES 2026 GRANTOR RETAINED ANNUITY TRUST NO. 1, for which the Reporting Person serves as trustee and is the sole annuitant. The Reporting Person disclaims beneficial ownership of such shares for purposes of Section 16 except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose.