Tax-withholding sale by Amylyx Pharmaceuticals (AMLX) Chief Legal Officer

Rhea-AI Filing Summary

Amylyx Pharmaceuticals Chief Legal Officer Gina Mazzariello reported an automatic sale of 6,844 shares of common stock on March 2, 2026 to cover tax withholding from vesting restricted stock units. The weighted average sale price was $14.5205 per share, and she held 134,430 shares afterward.

Insights

Equity compensation and insider trading analyst

Routine tax-withholding share sale; limited signal for investors.

The transaction shows Amylyx Pharmaceuticals’ Chief Legal Officer, Gina Mazzariello, disposing of 6,844 common shares on March 2, 2026 at a weighted average price of $14.5205. A footnote explains the shares were sold automatically to satisfy tax withholding on vesting restricted stock units.

Because the sale was required to cover taxes and was not at the executive’s discretion, it is generally viewed as routine equity-compensation administration rather than an active portfolio decision. After the sale, she retained 134,430 shares, indicating a continued substantial stake.

The filing also notes that individual trade prices ranged from $14.400 to $15.070, with the weighted average reported. Further details on each price tranche are available to regulators upon request, but for most investors the key takeaway is that this is a standard tax-related disposal.

Insider Trade Summary

Net Seller: 6,844 shares ($99,378)

Net Sell 1 txn

Insider Mazzariello Gina

Role Chief Legal Officer

Sold 6,844 shs ($99K)

Type	Security	Shares	Price	Value
Sale	Common Stock	6,844	$14.5205	$99K

Holdings After Transaction: Common Stock — 134,430 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 $14.400 to $15.070. 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^*

Mazzariello Gina

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

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	03/02/2026		S(1)		6,844(1)	D	$14.5205(2)	134,430	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 $14.400 to $15.070. 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	03/04/2026
	** 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 Amylyx Pharmaceuticals (AMLX) report for Gina Mazzariello?

Amylyx Pharmaceuticals reported that Chief Legal Officer Gina Mazzariello sold 6,844 shares of common stock. The sale occurred on March 2, 2026, and was tied to tax withholding on vesting restricted stock units, rather than a discretionary stock sale decision.

At what price were the Amylyx Pharmaceuticals (AMLX) shares sold in this Form 4?

The reported weighted average sale price was $14.5205 per share. Footnotes state the shares were sold in multiple transactions at prices ranging from $14.400 to $15.070, with full price-by-lot details available to SEC staff upon request if needed.

Why did Amylyx Pharmaceuticals’ Chief Legal Officer sell 6,844 AMLX shares?

The shares were sold to cover tax withholding obligations from vesting restricted stock units. According to the filing, these sales were automatic and not at Gina Mazzariello’s discretion, making them a routine equity-compensation tax event rather than an active investment decision.

How many Amylyx Pharmaceuticals (AMLX) shares does Gina Mazzariello hold after the reported sale?

After the reported transaction, Gina Mazzariello beneficially owned 134,430 shares of Amylyx Pharmaceuticals common stock. This remaining position, disclosed directly in the Form 4, indicates she continues to have a significant equity interest in the company following the tax-related sale.

Is the Amylyx Pharmaceuticals (AMLX) insider sale considered open-market selling?

The transaction is coded as an open-market sale but was executed automatically to cover tax withholding. Footnotes clarify the sale related to vesting restricted stock units and was not at the reporting person’s discretion, distinguishing it from a typical voluntary open-market liquidation.

What does the price range disclosed in the Amylyx (AMLX) Form 4 mean for investors?

The filing notes a weighted average price of $14.5205, with trades between $14.400 and $15.070. This range simply reflects multiple execution prices during the automatic tax-withholding sale, and detailed breakdowns are available to SEC staff, not usually crucial for most investors.