Why a Top Biotech Holder Sold 115,000 Mirum Shares but Still Ended Up With $185 Million on the Line

Core Insights - Mirum is a biopharmaceutical company focused on therapies for rare and orphan diseases, particularly liver disorders, leveraging its drug development expertise to meet significant unmet medical needs [1] - The company has seen a substantial increase in its stock price, with shares priced at $79.26, reflecting an 89% increase over the past year, significantly outperforming the S&P 500's 15% rise [2] Financial Performance - Mirum reported third-quarter revenue of $133 million, representing a 47% increase year-over-year, and raised its full-year revenue guidance to between $500 million and $510 million, driven by strong sales of LIVMARLI and expanding bile acid medicine revenue [6] - The company's cash and investments reached $378 million by the end of the quarter, providing financial flexibility to support multiple pipeline developments without immediate dilution concerns [6] Shareholder Activity - Eventide Asset Management sold 114,922 shares of Mirum, reducing its stake but increasing the net position value by approximately $50.70 million due to the stock price surge [3][4] - Despite the sale, Mirum became the second-largest equity holding in Eventide's portfolio, indicating a strategic decision to maintain a significant position in a company with strong growth potential [5] Market Position - Mirum's focus on rare disease markets provides a competitive advantage by targeting high-value, underserved patient populations, which is critical for driving growth through proprietary product commercialization [1]