Amylyx director exercises options for 50,000 shares

Amylyx Pharmaceuticals, Inc. (AMLX) director Karen Firestone reported exercising stock options to acquire common shares on August 31, 2026.

Rhea-AI Filing Summary

Amylyx Pharmaceuticals, Inc. (AMLX) director Karen Firestone reported exercising stock options to acquire common shares on August 31, 2026. She exercised two fully vested stock option grants covering a total of 50,000 shares of Common Stock, at exercise prices of $1.76 and $5.05 per share, respectively. The filing does not show her post-transaction share balances, and no Rule 10b5-1 trading plan is reported.

Insider Trade Summary

50,000 shares exercised/converted

Exercise 4 txns

Insider Firestone Karen

Role Director

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy) F1	25,000	$0.00	$0.00
Exercise	Stock Option (right to buy) F1	25,000	$0.00	$0.00
Exercise	Common Stock	25,000	$1.76	$44K
Exercise	Common Stock	25,000	$5.05	$126K

Holdings After Transaction: Stock Option (right to buy) — 0 contracts (Direct); Common Stock — 116,900 shares (Direct)

Footnotes (1)

1. F1. This option is fully vested and exercisable.

Key Figures

Options exercised at $1.76: 25,000 shares Options exercised at $5.05: 25,000 shares Total shares acquired via exercise: 50,000 shares +2 more

5 metrics

Options exercised at $1.76 25,000 shares Stock option exercise into Common Stock at $1.76 per share on August 31, 2026

Options exercised at $5.05 25,000 shares Stock option exercise into Common Stock at $5.05 per share on August 31, 2026

Total shares acquired via exercise 50,000 shares Aggregate Common Stock received from both option exercises on August 31, 2026

Exercise price (first grant) $1.76 per share Conversion or exercise price for one stock option grant expiring June 5, 2034

Exercise price (second grant) $5.05 per share Conversion or exercise price for one stock option grant expiring June 4, 2035

Key Terms

Stock Option (right to buy), derivative security, Common Stock, Rule 10b5-1

4 terms

Stock Option (right to buy) financial

"The reporting person held a Stock Option (right to buy) that was exercised"

derivative security financial

"Transactions coded as an exercise or conversion of derivative security"

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

Common Stock financial

"Underlying security title reported as Common Stock acquired upon exercise"

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

Rule 10b5-1 regulatory

"A document-level checkbox indicates Rule 10b5-1 trading plan status"

Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did AMLX director Karen Firestone report?

Karen Firestone reported exercising stock options to acquire 50,000 shares of Amylyx Pharmaceuticals Common Stock on August 31, 2026, through two separate option exercises.

How many Amylyx Pharmaceuticals (AMLX) options did Karen Firestone exercise?

She exercised options covering a total of 50,000 shares of Amylyx Pharmaceuticals Common Stock, split into two blocks of 25,000 shares each from separate option grants.

What were the exercise prices for the AMLX options exercised by Karen Firestone?

The reported stock option exercises were for 25,000 shares at $1.76 per share and 25,000 shares at $5.05 per share of Amylyx Pharmaceuticals Common Stock.

Was Karen Firestone’s AMLX option exercise under a Rule 10b5-1 trading plan?

No. The filing indicates no Rule 10b5-1 trading plan applies to these transactions; the plan-related checkbox is not marked as being used.

Did Karen Firestone sell any Amylyx Pharmaceuticals (AMLX) shares in this Form 4?

No. The Form 4 reports only option exercises and resulting share acquisitions. There are no reported open-market or other sales of Amylyx Pharmaceuticals Common Stock in this filing.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 09/02/2026 - 04:01 PM EDT Accepted by SEC EDGAR 09/02/2026 - 04:00 PM EDT Learn about SEC filing dates

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^*

Firestone Karen

(Last) (First) (Middle)

C/O AMYLYX PHARMACEUTICALS, INC.

55 CAMBRIDGE PARKWAY, SUITE 6W

(Street)

CAMBRIDGE MASSACHUSETTS 02142

(City) (State) (Zip)

UNITED STATES

(Country)

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
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/31/2026

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

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

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

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	08/31/2026		M		25,000	A	$1.76	91,900	D
Common Stock	08/31/2026		M		25,000	A	$5.05	116,900	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
Stock Option (right to buy)	$1.76	08/31/2026		M			25,000	(1)	06/05/2034	Common Stock	25,000	$0	0	D
Stock Option (right to buy)	$5.05	08/31/2026		M			25,000	(1)	06/04/2035	Common Stock	25,000	$0	0	D

Explanation of Responses:

1. This option is fully vested and exercisable.

	/s/ Joshua B. Cohen, as Attorney in Fact	09/02/2026
	** 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.
* Form 4: SEC 1474 (03-26)