MSCI adopted a new rule governing Strategy and other digital asset treasury firms that will keep their index weightings from growing as they issue more shares to buy bitcoin. MSTR stock jumped in after-hours action following the announcement, though the bitcoin price edged up only slightly, reversing part of the day's loss. Investors in Strategy, whose nearly $63 billion bitcoin stash makes it the largest corporate holder of the cryptocurrency, had been bracing for MSCI's decision, which had been expected by Jan. 15.