SCHEDULE: Driehaus Capital Management Reduces Definium Therapeutics Stake

Driehaus Capital Management LLC has amended its Schedule 13G filing to report a decrease in its beneficial ownership of Definium Therapeutics, Inc. common stock to 5.36% as of June 30, 2026.

Summary

• Driehaus Capital Management LLC (DCM) has filed an amendment to its Schedule 13G, reporting a change in its beneficial ownership of Definium Therapeutics, Inc. common stock.
• As of June 30, 2026, DCM beneficially owned 6,845,276 shares, representing 5.36% of the class of securities.
• This represents a decrease from its previous ownership of 6.64% as of December 31, 2025.
• The filing notes that the issuer changed its name from Mind Medicine (MindMed), Inc. to Definium Therapeutics, Inc. on January 12, 2026.
• DCM manages these shares on a fully discretionary basis for numerous clients.

Sentiment

Score: 4

Explanation: StockSavvy.ai views this filing as neutral to slightly negative, primarily due to a reduction in ownership percentage, indicating a potential shift in investment strategy or market conditions.

Positives

• DCM continues to hold a significant stake (5.36%) in Definium Therapeutics, Inc., indicating ongoing strategic interest.
• The shares are managed on a fully discretionary basis, suggesting professional management of the investment.

Negatives

• DCM's beneficial ownership has decreased from 6.64% to 5.36% between December 31, 2025, and June 30, 2026.
• The reduction in ownership percentage may signal a re-evaluation of the investment or a response to market conditions.

Risks

• The filing does not explicitly detail risks associated with the investment or the company's operations.
• Potential future changes in DCM's ownership percentage could impact the stock price.

Future Outlook

The filing does not contain specific forward-looking statements or guidance from the company. It solely reports changes in beneficial ownership by Driehaus Capital Management LLC.

Management Comments

• "The issuer changed its name from Mind Medicine (MindMed), Inc. to Definium Therapeutics, Inc. on January 12, 2026."
• "This amendment is filed to reflect the change in our percentage of ownership of Definium Therapeutics, Inc. (DFTX)."
• "DCM owned 5.36% of DFTX as of June 30, 2026, down from 6.64% as of December 31, 2025."
• "The shares reported by Driehaus Capital Management LLC (DCM) are held by numerous clients on a fully discretionary basis in accounts managed by DCM."
• "To the best of DCM's knowledge, none of the referenced clients have the right to receive dividends or direct proceeds from the sale of interests relating to more than 5% of the class."

Industry Context

StockSavvy.ai notes that changes in significant institutional ownership, as reported in Schedule 13G filings, are common in the biotechnology and pharmaceutical sectors. Such shifts can reflect evolving investment theses, portfolio rebalancing, or responses to clinical trial results or regulatory news.

Stakeholder Impact

• Shareholders may interpret the reduction in DCM's stake as a signal of potential future price movements, either positive or negative, depending on the underlying reasons for the reduction.
• The filing itself does not directly impact employees, customers, or suppliers, but any subsequent stock price changes could indirectly affect employee stock options or company valuation.

Next Steps

• Driehaus Capital Management LLC will continue to manage its clients' investments in Definium Therapeutics, Inc. on a discretionary basis.
• Future amendments to Schedule 13G will be filed if ownership levels change significantly.

Key Dates

Recommendation

Based on this filing alone, which primarily reports a reduction in ownership by a significant institutional investor without providing new operational or financial data, a 'hold' recommendation is appropriate. The decrease in stake suggests a potential shift in sentiment or strategy by Driehaus Capital Management, warranting observation rather than immediate action. Further analysis of Definium Therapeutics' underlying business performance and future prospects is needed for a more definitive recommendation.

Keywords

Definium Therapeutics, Driehaus Capital Management, Schedule 13G, Beneficial Ownership, Common Stock, Investment Management, Shareholder