Form 4: Disc Medicine Director Sells Shares Under 10b5-1 Plan

Disc Medicine Director Kevin Bitterman sold 395 shares of common stock at $60.95 per share under a pre-arranged trading plan.

Summary

• Kevin Bitterman, a Director of Disc Medicine, Inc. (IRON), sold 395 shares of the company's common stock.
• The sale took place on August 5, 2025, at a price of $60.95 per share.
• The transaction was executed pursuant to a Rule 10b5-1 trading plan, which was established on January 31, 2025.
• Following this sale, Kevin Bitterman's beneficial ownership of Disc Medicine shares is entirely indirect, totaling 1,096,631 shares (625,082 + 420,549 + 51,000).
• These shares are held across three Atlas Venture funds: Atlas Venture Opportunity Fund I, LP (625,082 shares), Atlas Venture Opportunity Fund II, LP (420,549 shares), and Atlas Venture Fund XII, L.P. (51,000 shares).
• Bitterman disclaims beneficial ownership of these indirect holdings except to the extent of his pecuniary interest.

Sentiment

Score: 5

Explanation: The sale was pre-planned under a 10b5-1 plan, which mitigates negative sentiment typically associated with insider sales, making it a neutral event.

Negatives

• A Director sold 395 shares of common stock, reducing their direct holdings in the company.

Related Party Transactions

• Kevin Bitterman holds indirect beneficial ownership in Disc Medicine, Inc. through his membership in the general partners of Atlas Venture Opportunity Fund I, LP, Atlas Venture Opportunity Fund II, LP, and Atlas Venture Fund XII, L.P.

Stakeholder Impact

• Shareholders: A minor reduction in direct insider ownership, potentially viewed neutrally given the 10b5-1 plan.

Key Dates

Recommendation

The transaction is a routine, pre-planned sale of a small number of shares by a director, executed under a Rule 10b5-1 plan. This type of transaction typically does not signal new material information about the company's prospects and therefore does not warrant a change in investment recommendation based solely on this filing. The director retains significant indirect beneficial ownership.

Keywords

Disc Medicine, IRON, SEC Form 4, Insider Trading, Stock Sale, Director, Rule 10b5-1, Biotechnology, Pharmaceuticals, Atlas Venture