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

Kevin Bitterman, a Director at Disc Medicine, Inc., sold 2,287 shares of common stock for approximately $139,580 under a pre-arranged trading plan.

Summary

• Kevin Bitterman, a Director of Disc Medicine, Inc. (IRON), executed a sale of 2,287 shares of common stock.
• The transaction occurred on August 22, 2025, at a weighted average price of $61.03 per share, totaling approximately $139,580.
• The sale was conducted pursuant to a Rule 10b5-1 trading plan established on January 31, 2025.
• Following the transaction, Mr. Bitterman's indirect beneficial ownership includes 590,621 shares held by Atlas Venture Opportunity Fund I, LP, 420,549 shares held by Atlas Venture Opportunity Fund II, LP, and 51,000 shares held by Atlas Venture Fund XII, L.P.
• Mr. Bitterman disclaims beneficial ownership of the indirectly held securities except to the extent of his pecuniary interest therein.

Sentiment

Score: 5

Explanation: The sentiment is neutral to slightly negative. While it's an insider sale, the fact that it's under a 10b5-1 plan mitigates the negative perception, suggesting a pre-scheduled portfolio management action rather than a reaction to adverse company news. The amount sold is also relatively small compared to the total indirect holdings.

Negatives

• An insider sale, even under a 10b5-1 plan, can sometimes be perceived as a slight negative signal by investors, indicating a director's decision to reduce their direct equity exposure.

Risks

• While the sale was pre-planned, significant insider selling over time could potentially signal a lack of confidence in the company's future prospects, which is a risk for investors.

Future Outlook

The filing does not contain any forward-looking statements or guidance regarding the company's future performance or strategic direction.

Industry Context

This Form 4 filing is a routine disclosure of an insider stock transaction and does not provide specific insights into broader industry trends or competitive landscape. Such sales are common for directors managing personal portfolios, especially when executed under pre-arranged 10b5-1 plans.

Related Party Transactions

• Kevin Bitterman's indirect beneficial ownership is through Atlas Venture Opportunity Fund I, LP, Atlas Venture Opportunity Fund II, LP, and Atlas Venture Fund XII, L.P., where he is a member of the general partner's general partner (Associates I LLC, Associates II LLC, and Associates XII LLC, respectively). He disclaims beneficial ownership except for his pecuniary interest.

Stakeholder Impact

• Shareholders may view this as a routine, pre-planned transaction, but some might interpret any insider selling as a minor negative signal regarding the stock's short-term prospects.

Key Dates

Recommendation

The sale by Director Kevin Bitterman was executed under a Rule 10b5-1 trading plan, indicating it was a pre-scheduled, non-discretionary transaction. The volume of shares sold (2,287) is relatively small compared to his significant indirect holdings. This type of transaction is common for executives managing personal liquidity and does not typically signal a fundamental shift in the company's outlook. Therefore, a 'hold' recommendation is appropriate, as this specific filing does not present new information warranting a change in investment thesis, but rather a routine insider disclosure.

Keywords

Disc Medicine, IRON, Form 4, Insider Sale, Kevin Bitterman, 10b5-1 Plan, Director, Stock Transaction