[Form 4] Amylyx Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Gina Mazzariello, Chief Legal Officer of Amylyx Pharmaceuticals (AMLX), reported two Rule 10b5-1 sales totaling 30,000 common shares on August 12, 2025 and August 13, 2025. The August 12 sales comprised 15,000 shares at a weighted average price of $8.0735 (trades ranged $7.82–$8.27) and the August 13 sales comprised 15,000 shares at a weighted average price of $8.3364 (trades ranged $8.13–$8.47). After these transactions the reporting person beneficially owned 156,969 shares. The sales were executed under a 10b5-1 trading plan adopted on May 13, 2025. The Form 4 was filed and signed by an attorney in fact on August 14, 2025.

Positive

• Sales executed under a Rule 10b5-1 plan, indicating prearranged transactions rather than opportunistic trading
• Full disclosure of weighted-average prices and price ranges for the executed trades
• Reporting person identified with title (Chief Legal Officer) and Form 4 signed by attorney in fact

Negative

• Insider decreased holdings by 30,000 shares, reducing beneficial ownership to 156,969 shares
• Two sequential sales over consecutive days may attract investor attention despite being under a 10b5-1 plan

Insights

Securities Analyst

TL;DR: Insider sold 30,000 AMLX shares under a 10b5-1 plan; post-sale holdings remain material at 156,969 shares.

The Form 4 discloses routine, prearranged sales rather than open-market ad hoc disposals, which preserves the affirmative defense under Rule 10b5-1. The transaction sizes and weighted-average prices are explicitly reported, enabling precise calculation of proceeds if needed. There is no disclosure here of option exercises or derivative activity—only straight common stock dispositions. For investors, the key facts are the sell dates, volumes, prices, and the continued beneficial ownership level.

Corporate Governance Expert

TL;DR: Sales occurred under a documented 10b5-1 plan, which aligns with governance best practices for scheduled insider trading.

The filer is the company Chief Legal Officer and properly identified relationship and filing status. The Form 4 includes the 10b5-1 adoption date and provides weighted-average price ranges for the executed trades. The filing appears complete and signed by an attorney in fact, meeting procedural requirements for Section 16 reporting.

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).

X

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.

43 THORNDIKE STREET

(Street)

CAMBRIDGE MA 02141

(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)
08/12/2025

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	08/12/2025		S(1)		15,000	D	$8.0735(2)	171,969	D
Common Stock	08/13/2025		S(1)		15,000	D	$8.3364(3)	156,969	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. The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan adopted on May 13, 2025.

2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $7.82 to $8.27. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

3. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $8.13 to $8.47. 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	08/14/2025
	** 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 did AMLX insider Gina Mazzariello sell?

She sold a total of 30,000 common shares of Amylyx Pharmaceuticals: 15,000 on 08/12/2025 and 15,000 on 08/13/2025.

At what prices were the AMLX shares sold?

The August 12 sales had a weighted average price of $8.0735 (individual trades ranged $7.82–$8.27). The August 13 sales had a weighted average price of $8.3364 (individual trades ranged $8.13–$8.47).

Were these sales part of a planned trading arrangement?

Yes. The sales were effected pursuant to a Rule 10b5-1 trading plan adopted on May 13, 2025.

How many AMLX shares does the reporting person own after the transactions?

After the reported sales the reporting person beneficially owned 156,969 shares.

Who filed and signed the Form 4?

The Form 4 was signed by Joshua B. Cohen, as Attorney in Fact, with the signature date of 08/14/2025.