Automatic tax sale: Amylyx (NASDAQ: AMLX) Co-CEO sells shares

Rhea-AI Filing Summary

Amylyx Pharmaceuticals Co-CEO Justin B. Klee reported an automatic tax-related share sale. On 02/02/2026, he sold 15,500 shares of Amylyx common stock at a weighted average price of $14.685 per share to cover tax withholding tied to vesting restricted stock units.

After this transaction, Klee still beneficially owned 3,363,898 Amylyx shares directly. The filing notes the sales were required for tax withholding and were not made at his discretion, and that individual sale prices ranged from $14.510 to $14.760.

Insider Trade Summary

Net Seller: 15,500 shares ($227,618)

Net Sell 1 txn

Insider Klee Justin B.

Role Co-Chief Executive Officer

Sold 15,500 shs ($228K)

Type	Security	Shares	Price	Value
Sale	Common Stock	15,500	$14.685	$228K

Holdings After Transaction: Common Stock — 3,363,898 shares (Direct)

Footnotes (1)

1. Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. Such sales were automatic and not at the discretion of the Reporting Person. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $14.510 to $14.760. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Klee Justin B.

(Last) (First) (Middle)

C/O AMYLYX PHARMACEUTICALS, INC.

55 CAMBRIDGE PARKWAY, SUITE 6W

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Amylyx Pharmaceuticals, Inc. [ AMLX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Co-Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/02/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/02/2026		S(1)		15,500(1)	D	$14.685(2)	3,363,898	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

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

2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $14.510 to $14.760. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

	/s/ Joshua B. Cohen, as Attorney in Fact	02/04/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did AMLX Co-CEO Justin B. Klee report?

Justin B. Klee reported selling 15,500 shares of Amylyx Pharmaceuticals common stock. The transaction occurred on February 2, 2026, and was disclosed in a Form 4 filing. It was tied to restricted stock unit vesting rather than a discretionary open-market sale.

Why did Amylyx (AMLX) Co-CEO Justin B. Klee sell 15,500 shares?

The 15,500 shares were sold to cover tax withholding obligations from vesting restricted stock units. The filing explains these sales were automatic and not at Klee’s discretion, meaning they were triggered by tax requirements rather than an elective decision to reduce his holdings.

How many AMLX shares does Justin B. Klee own after the reported sale?

After the sale, Justin B. Klee beneficially owned 3,363,898 shares of Amylyx common stock directly. This figure reflects his holdings following the 15,500-share sale related to tax withholding obligations and provides context that his remaining ownership stake is still substantial.

What was the sale price for Justin B. Klee’s Amylyx (AMLX) shares?

The weighted average sale price reported was $14.685 per share. The filing notes the shares were sold in multiple transactions at prices ranging from $14.510 to $14.760, and detailed trade breakdowns can be provided to SEC staff upon request.

Was Justin B. Klee’s AMLX share sale discretionary or automatic?

The sale was automatic, not discretionary. The filing states the shares were required to be sold to cover tax withholding obligations from vesting restricted stock units, indicating the transaction was mechanically driven by tax rules rather than an active portfolio management decision.

What role does Justin B. Klee hold at Amylyx Pharmaceuticals (AMLX)?

Justin B. Klee serves as a Director and Co-Chief Executive Officer at Amylyx Pharmaceuticals. His dual role as both board member and senior executive makes his equity holdings and any reported share transactions particularly relevant for understanding leadership alignment with shareholders.