Form 4: Mirum CEO Sells Shares for Tax Obligations

Mirum Pharmaceuticals CEO Christopher Peetz sold 9,108 shares of common stock to cover tax withholding obligations related to restricted stock unit vesting.

Summary

• Christopher Peetz, the Chief Executive Officer and a Director of Mirum Pharmaceuticals, Inc. (MIRM), reported a sale of common stock.
• The transaction involved the disposition of 9,108 shares of common stock on February 2, 2026.
• The shares were sold at a price of $103.3035 per share.
• The purpose of the sale was to cover tax withholding obligations associated with the vesting of restricted stock units.
• Following the transaction, Mr. Peetz directly beneficially owns 160,294 shares and indirectly owns 187,500 shares through The Peetz Family Trust.
• The transaction was made pursuant to a Rule 10b5-1(c) plan, indicating it was pre-arranged.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral event. The sale is a routine, non-discretionary transaction to cover tax liabilities from equity vesting, which is common for executives.

Positives

• The transaction was executed to cover tax withholding obligations, which is a common and often pre-planned event for executives receiving equity compensation.
• The sale was conducted under a Rule 10b5-1(c) plan, indicating it was pre-arranged and not based on new material non-public information.

Negatives

• A reduction in direct insider ownership, albeit for a specific tax-related purpose.

Risks

• While this specific transaction is routine, any reduction in insider ownership could be perceived by some investors as a minor negative signal, potentially impacting investor sentiment if not understood in context.

Industry Context

StockSavvy.ai notes that sales of company stock by executives to cover tax obligations upon the vesting of restricted stock units are a standard practice in executive compensation. Such transactions, especially when conducted under a Rule 10b5-1 plan, are generally considered routine and do not typically signal a change in management's outlook on the company's future performance or a lack of confidence, unlike discretionary sales.

Stakeholder Impact

• Shareholders: A minor, routine reduction in direct insider ownership, generally not indicative of a change in company fundamentals.

Key Dates

Recommendation

The transaction is a routine, non-discretionary sale of shares by the CEO to cover tax obligations related to restricted stock unit vesting, executed under a pre-arranged 10b5-1 plan. This type of insider activity is common and typically does not reflect a change in the company's fundamental outlook or warrant a change in investment recommendation. Therefore, a 'hold' recommendation is appropriate as this filing does not provide new information to alter the investment thesis.

Keywords

Mirum Pharmaceuticals, MIRM, Christopher Peetz, CEO, Director, Form 4, Insider Trading, Stock Sale, Tax Withholding, Restricted Stock Units, Equity Compensation, Rule 10b5-1