Strategy, formerly MicroStrategy, could lose its place in major global stock indexes under new rules MSCI approved on Thursday. According to NS3.AI, exclusion would generally require ETFs tracking the affected indexes to sell MSTR shares when they rebalance.

Strategy estimates that MSCI-linked funds hold roughly 13 million shares, or around 3.1% of Strategy's basic shares outstanding. The company disputes MSCI's distinction between investment vehicles and operating businesses and called the proposal misguided.

MSCI will publish the affected-company list on November 11, and the rules take effect after November 30. Existing constituents are protected by a two-annual-filing test before removal.