Mirum Pharmaceuticals (MIRM) traded lower after investors focused on a resale registration statement tied to the company’s Bluejay Therapeutics acquisition and related financing activity. The filing registers 8,960,998 shares of common stock for potential resale by selling stockholders, a setup that can create an overhang when markets price in incremental supply and possible profit-taking.

The registered total includes multiple buckets of stock issued in January and February 2026 in connection with the Bluejay transaction, shares held back for indemnification-related obligations, additional shares issued in private placements that followed the deal closing, and shares underlying pre-funded warrants. While the registration itself does not necessarily mean immediate selling, it can remove friction for selling stockholders to distribute shares over time.

MIRM has been trading near the mid-$90s after a sharp multi-month advance, making the stock more sensitive to any perceived supply increase. With the resale registration highlighting a defined pool of shares that could enter the market, short-term holders often step aside until expected selling pressure becomes clearer, contributing to today’s pullback.