SCHEDULE: Muneer Satter Boosts Annexon Stake to 7.2%

Muneer A. Satter, through Alerce Medical, increased his beneficial ownership in Annexon, Inc. to 7.2% by purchasing an additional 2.3 million shares for approximately $8.7 million.

Summary

• Muneer A. Satter, through Alerce Medical, acquired an additional 2,322,613 shares of Annexon, Inc. Common Stock between November 17 and November 21, 2025.
• The shares were purchased on Nasdaq for an average price of $3.73 per share, excluding commissions, totaling approximately $8.7 million.
• The source of funds for these acquisitions was working capital of Alerce Medical, drawn from capital committed by its limited partners.
• Following these purchases, Mr. Satter's aggregate beneficial ownership in Annexon, Inc. stands at 10,444,134 shares.
• This represents 7.2% of Annexon, Inc.'s Common Stock, calculated based on 145,261,154 shares outstanding, which includes 144,545,657 shares disclosed by the Issuer, 613,497 shares from warrants, and 102,000 shares from stock options exercisable within 60 days.

Sentiment

Score: 8

Explanation: The significant increase in beneficial ownership by a prominent investor like Muneer A. Satter is a strong positive signal, indicating high confidence in Annexon, Inc.'s value and future potential. This action suggests a belief that the company's stock is undervalued or poised for growth.

Positives

• A significant investor, Muneer A. Satter, increased his stake in Annexon, Inc., signaling strong confidence in the company's future prospects.
• The substantial investment of approximately $8.7 million demonstrates a material commitment from a prominent financial professional.

Future Outlook

This filing does not contain any forward-looking statements or guidance from Annexon, Inc. management; it solely reports an investor's change in beneficial ownership.

Industry Context

This filing reflects an individual investor's increased conviction in Annexon, Inc., rather than a broader industry trend or competitive development. Such an increase in stake by a notable investor can sometimes be interpreted by the market as a positive signal for the company's prospects within its sector.

Related Party Transactions

• The shares were purchased by Alerce Medical, an entity associated with the reporting person, Muneer A. Satter, indicating an acquisition by a related party.

Stakeholder Impact

• Shareholders may view the increased stake by a significant investor as a vote of confidence, potentially leading to increased investor interest and positive sentiment towards the stock.

Key Dates

Recommendation

A seasoned investor increasing their stake significantly, especially through open market purchases, often signals strong conviction in the company's future performance or perceived undervaluation. This action by Muneer A. Satter suggests a belief in Annexon, Inc.'s long-term potential, making it a compelling 'buy' signal for other investors who align with such insider confidence.

Keywords

Annexon Inc, Muneer A Satter, Alerce Investment Management, Schedule 13D, Beneficial Ownership, Stock Purchase, Investor Stake, Common Stock