CEO of Mirum Pharmaceuticals Executes Routine Tax Sale Amid Active Insider Trading Schedule

Insider Activity Highlights a Strategic Shift

On February 2, 2026 Mirum Pharmaceuticals’ chief executive, Christopher Peetz, sold 9,108 shares of common stock at $103.30 per share. The transaction was a routine tax‑withholding relief tied to vested restricted stock units, yet it sits on a backdrop of a highly active insider calendar. Within the last month the CEO has moved a total of roughly 30,000 shares in and out of the company’s equity—buying 40,000 shares in August 2025, adding 43,500 restricted units, and selling more than 60,000 shares in January 2026. This pattern of frequent trading suggests a balanced approach: the CEO is willing to lock in gains when the share price is favorable while retaining a substantial stake (187,500 shares) that still represents a significant voting interest.

What It Means for Investors

The timing of the sale coincides with Mirum’s steep 28‑month‑high trajectory, yet the company remains on the margin of its 52‑week high. Investors watching the CEO’s activity should note that the sale was for tax purposes rather than a signal of confidence erosion. However, the broader insider market has been relatively quiet—only a handful of other executives made sizeable moves, with Radovich, the COO, selling 2,631 shares the same day, and the SVP of Global Controller buying 968 shares. The muted volume indicates that the leadership team is not attempting to dramatically alter market perception, but the consistent buying in the past months signals a long‑term commitment to the company’s therapeutic pipeline.

Peetz Christopher: A Profile of Consistency

Peetz’s transaction history shows a pattern of strategic ownership adjustments. Since August 2025, he has alternated between purchasing large blocks of restricted units and selling shares to cover tax obligations. In January 2026 alone, he bought 75,000 restricted units and 43,500 restricted units, while also selling 6,831 shares at $96.19 and 7,098 shares at $93.33. The CEO’s net position—over 187,000 shares—keeps him within the “large‑shareholder” bracket, giving him both influence and a vested interest in the company’s long‑term prospects. His trades suggest a focus on maintaining liquidity while preserving a majority stake that aligns his incentives with shareholders.

Strategic Outlook for Mirum

Mirum’s valuation metrics—negative earnings and a P/E of –122—reflect a company still in the growth phase, developing therapies for cholestatic liver diseases. The stock’s recent 89% year‑to‑date rally signals market optimism, but the volatility range from $36.88 to $105.64 warns of potential downside. Insider activity, including Peetz’s recent sale, is unlikely to dampen that momentum but should be viewed in context: a CEO who buys and holds significant equity while executing routine tax‑related sales tends to reinforce confidence rather than undermine it. For investors, the key will be monitoring forthcoming clinical milestones and revenue guidance, as these will likely have the most decisive impact on the stock’s trajectory.