SCHEDULE: Atlas Venture Cuts Disc Medicine Stake to 6.2%

Atlas Venture entities have significantly reduced their beneficial ownership in Disc Medicine, Inc. through a series of common stock sales.

Summary

• Atlas Venture entities, including Atlas X, Atlas XII, Atlas Venture Opportunity Fund I, L.P. (AVOF), and Atlas Venture Opportunity Fund II, L.P. (AVOF II), collectively hold 2,148,984 shares of Disc Medicine, Inc. common stock.
• This aggregate holding represents 6.2% of Disc Medicine's outstanding common stock, calculated based on 34,765,581 shares outstanding as of July 31, 2025.
• Atlas X and AVOF executed multiple sales of common stock between July 18, 2025, and August 14, 2025, totaling 235,472 shares.
• The sales by Atlas X amounted to 150,877 shares, while AVOF sold 84,595 shares.
• Weighted average prices for these sales ranged from $60.95 to $61.17 per share.
• This Schedule 13D filing is Amendment No. 4 to the initial statement filed on February 16, 2021, reflecting the updated beneficial ownership.

Sentiment

Score: 3

Explanation: The sentiment is negative due to a significant institutional investor reducing its stake in the company through multiple sales, which can signal diminished confidence or a strategic exit. While not a direct negative on the company's operations, it's a negative signal from a key shareholder.

Negatives

• A significant reduction in beneficial ownership by Atlas Venture, a major institutional investor group, indicates a potential shift in their investment thesis or a strategic divestment.
• The consistent selling of 235,472 shares over a short period by Atlas X and AVOF could signal diminished confidence in Disc Medicine's near-term prospects or valuation.
• The divestment by a prominent venture capital firm may be perceived negatively by the market, potentially impacting investor sentiment.

Risks

• Reduced institutional support: The decrease in ownership by Atlas Venture, a significant early investor, could signal a lack of future growth potential or concerns about the company's direction.
• Potential for further sales: The ongoing sales activity by Atlas Venture entities suggests they may continue to divest their holdings, which could put downward pressure on the stock price.
• Market perception: Other investors may interpret the divestment by a prominent venture capital firm as a negative signal, potentially impacting investor sentiment and the stock's valuation.

Future Outlook

The filing does not provide any forward-looking statements or guidance regarding Disc Medicine, Inc.'s future operations or financial performance.

Management Comments

• No direct management comments or notable quotes from Disc Medicine, Inc. management are included in this filing. The filing is signed by Ommer Chohan as CFO of Atlas Venture entities.

Industry Context

This filing reflects a significant institutional investor's decision to reduce its stake in a biotechnology company. While specific to Disc Medicine, such divestments by venture capital firms can sometimes indicate a shift in investment strategy or a re-evaluation of the company's long-term prospects within the competitive biotech landscape. It does not provide broader industry trends.

Stakeholder Impact

• Shareholders: Existing shareholders may experience downward pressure on stock price due to increased supply from the sales and potential negative sentiment. New investors might view the reduced institutional stake as a cautionary signal.
• Company Management: May face questions regarding the reasons for the significant investor's divestment and its implications for future capital raising or strategic partnerships.

Next Steps

• The filing does not specify any future actions, events, or milestones for Disc Medicine, Inc. or the reporting persons beyond the ongoing beneficial ownership reporting requirements.

Key Dates

Recommendation

The significant reduction in beneficial ownership by Atlas Venture, a prominent institutional investor, through consistent sales over a short period, indicates a potential loss of confidence or a strategic divestment. This action by a major shareholder can signal underlying concerns about the company's future prospects or valuation, leading to negative market sentiment and potential downward pressure on the stock price. For a seasoned investor, this type of insider selling, especially from a venture capital firm that was an early backer, often warrants a 'sell' recommendation as it suggests a lack of conviction in the company's continued growth or a belief that the stock has reached its peak value for the foreseeable future.

Keywords

Disc Medicine, Atlas Venture, Schedule 13D, Common Stock Sales, Beneficial Ownership, Institutional Investor, Biotechnology, Healthcare, SEC Filing, Shareholder Activity