Form 4: Annexon Director Boosts Stake with $5M Stock Purchases

Annexon Director Muneer A. Satter significantly increased his indirect beneficial ownership in the company through a series of common stock purchases totaling 1.5 million shares over three days in November 2025.

Summary

• Muneer A. Satter, a Director and 10% Owner of Annexon, Inc. (ANNX), reported a series of common stock acquisitions.
• A total of 1,500,000 shares of common stock were purchased over three consecutive days: 500,000 shares on November 17, 2025; 500,000 shares on November 18, 2025; and 500,000 shares on November 19, 2025.
• The shares were acquired at weighted average prices of $2.99, $3.18, and $3.94, respectively.
• All shares were purchased by Alerce Medical Technology Partners, L.P., an entity for which Muneer A. Satter has sole voting and dispositive power.
• Following these transactions, Muneer A. Satter's indirect beneficial ownership in Annexon, Inc. increased to 8,906,024 shares.
• The beneficial ownership includes shares held by the Muneer A. Satter Revocable Trust (240,000 shares), various other trusts and entities (567,240 shares), Satter Medical Technology Partners, L.P. (1,147,738 shares), and Alerce Medical Technology Partners, L.P. (6,951,046 shares).

Sentiment

Score: 9

Explanation: The significant insider buying by a director and 10% owner, totaling over $5 million, indicates strong confidence in the company's valuation and future prospects, which is a highly positive signal for investors.

Positives

• Significant insider buying by a director and 10% owner signals strong confidence in the company's future prospects.
• The director invested over $5 million in additional shares, demonstrating a substantial personal commitment.
• The purchases were made at varying price points, including higher prices, suggesting a belief in continued value appreciation.

Future Outlook

This filing is a transactional disclosure and does not contain explicit forward-looking statements or guidance from the company or management regarding future performance or strategic direction.

Industry Context

Insider buying, particularly by a director and significant shareholder, is generally viewed as a positive indicator in the market, suggesting that those with intimate knowledge of the company believe its stock is undervalued or poised for growth. This action by Muneer A. Satter could be interpreted as a strong vote of confidence in Annexon's pipeline or strategic initiatives, potentially differentiating it from competitors who may not see similar insider investment.

Related Party Transactions

• Muneer A. Satter, a Director and 10% Owner, indirectly acquired 1,500,000 shares of Annexon common stock through Alerce Medical Technology Partners, L.P., an entity over which he has sole voting and dispositive power. This constitutes a related party transaction as it involves a key insider and entities under their control.

Stakeholder Impact

• Shareholders may view this significant insider purchase as a strong signal of management's confidence, potentially leading to increased investor interest and positive sentiment.
• The increased ownership by a director aligns management's interests more closely with those of long-term shareholders.

Key Dates

Recommendation

The substantial insider buying by a director and 10% owner, Muneer A. Satter, who invested over $5 million in additional shares, is a strong positive signal. Such actions typically indicate that insiders believe the company's stock is undervalued or has significant upside potential. This increased alignment of interests and vote of confidence from a knowledgeable party suggests a favorable outlook for the stock.

Keywords

Annexon, ANNX, Insider Buying, Director, Stock Purchase, Beneficial Ownership, Form 4, Alerce Medical Technology Partners