Form 4: Disc Medicine Director Sells Shares

Disc Medicine Director Kevin Bitterman reported the sale of 754 common shares at a weighted average price of $91.47 through affiliated investment funds.

Summary

• Kevin Bitterman, a Director of Disc Medicine, Inc. (IRON), reported the sale of common stock.
• The transactions occurred on December 17, 2025.
• A total of 754 shares were sold across three separate transactions.
• The weighted average sale price was $91.47 per share, with prices ranging from $91.2501 to $91.52.
• The shares were held indirectly through Atlas Venture Opportunity Fund I, LP (393 shares), Atlas Venture Opportunity Fund II, LP (213 shares), and Atlas Venture Fund XII, L.P. (148 shares).
• Following these transactions, the indirect beneficial ownership stands at 349,210 shares (Opportunity I), 337,485 shares (Opportunity II), and 14,013 shares (Atlas XII).
• Mr. Bitterman disclaims beneficial ownership of these securities except to the extent of his pecuniary interest.

Sentiment

Score: 5

Explanation: This is a routine disclosure of an insider stock sale, which does not inherently indicate positive or negative company performance or outlook. The sale amount is relatively small in the context of total holdings.

Negatives

• Insider selling, even if routine, can sometimes be viewed with slight caution by investors, though the amount here is small relative to total holdings.

Future Outlook

This filing does not contain any forward-looking statements or guidance.

Industry Context

This is a routine insider transaction disclosure and does not provide information related to broader industry trends or competitors.

Related Party Transactions

• The shares sold were held by investment funds (Atlas Venture Opportunity Fund I, LP, Atlas Venture Opportunity Fund II, LP, and Atlas Venture Fund XII, L.P.) where Kevin Bitterman is a member of the general partner's general partner.
• Mr. Bitterman disclaims beneficial ownership of these securities except to the extent of his pecuniary interest.

Stakeholder Impact

• Shareholders: Minor impact due to a relatively small insider sale. Could be interpreted as a slight negative signal, but often routine for fund managers.
• Employees, Customers, Suppliers, Creditors: No direct impact from this filing.

Key Dates

Keywords

Disc Medicine, IRON, Form 4, insider trading, stock sale, director, Kevin Bitterman, Atlas Venture, beneficial ownership