SCHEDULE: Adage Capital Discloses 6.39% Stake in Amylyx Pharma

Adage Capital Management, L.P., along with Robert Atchinson and Phillip Gross, reported a 6.39% beneficial ownership stake in Amylyx Pharmaceuticals, Inc. as of September 30, 2025.

Summary

• Adage Capital Management, L.P., Robert Atchinson, and Phillip Gross collectively reported beneficial ownership of 6,816,828 shares of Amylyx Pharmaceuticals, Inc. Common Stock.
• This ownership represents 6.39% of the company's outstanding Common Stock.
• The percentage is calculated based on 106,656,350 shares of Common Stock outstanding, as reported by Amylyx Pharmaceuticals, Inc. in its September 10, 2025 Prospectus and Form 8-K.
• The reporting persons hold shared voting power and shared dispositive power over all 6,816,828 shares.
• The securities were acquired and are held in the ordinary course of business, not for the purpose of changing or influencing control of the issuer.

Sentiment

Score: 7

Explanation: The disclosure of a significant beneficial ownership stake by a reputable investment firm like Adage Capital Management, L.P., without any stated intent to influence control, generally conveys a positive sentiment, suggesting confidence in the issuer's long-term value. It's a routine disclosure but the size of the stake is notable.

Positives

• A significant institutional investor, Adage Capital Management, L.P., maintains a substantial stake in Amylyx Pharmaceuticals, Inc., indicating continued confidence in the company's prospects.
• The filing confirms that the ownership is for investment purposes in the ordinary course of business, not for control-related activism.

Negatives

• No specific negative financial or operational information is disclosed in this beneficial ownership report.

Risks

• The filing itself does not detail specific risks related to Amylyx Pharmaceuticals, Inc.'s operations or financial health, as it is a disclosure of beneficial ownership.

Future Outlook

This filing does not contain any forward-looking statements or guidance from Amylyx Pharmaceuticals, Inc. regarding its future outlook.

Management Comments

• "To the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under §§ 240.14a-11."

Industry Context

This filing reflects an institutional investor's position in a biotechnology company. Such disclosures are common and provide transparency into significant ownership stakes, which can be a signal of investor confidence within the pharmaceutical sector.

Stakeholder Impact

• Shareholders: The disclosure provides transparency regarding a significant institutional holder, which can influence investor perception and potentially provide a degree of stability to the stock by indicating a large, long-term holder.

Key Dates

Recommendation

This Schedule 13G filing primarily serves as a disclosure of a significant ownership stake by Adage Capital Management, L.P. in Amylyx Pharmaceuticals, Inc. While the substantial stake (6.39%) by a prominent institutional investor can be viewed as a positive signal of confidence, the filing itself does not provide new operational or financial data to warrant a 'buy' or 'sell' recommendation. It confirms a significant existing position held for investment purposes. Therefore, a 'hold' recommendation is appropriate, advising investors to maintain their current positions while awaiting further fundamental updates from the company.

Keywords

Amylyx Pharmaceuticals, Adage Capital Management, Beneficial Ownership, Schedule 13G, Common Stock, Institutional Investor, Biotechnology, Pharmaceuticals