Strive Asset Management, which oversees about $2.2 billion in assets, said it expects MicroStrategy—led by Bitcoin advocate Michael Saylor—to be added to the S&P 500 at the index’s next monthly rebalancing. The asset manager cited passive-fund flows as a catalyst that could lift demand for the stock if the inclusion occurs. Separately, several market watchers said Saylor plans to disclose another Bitcoin purchase tomorrow. MicroStrategy has built one of the world’s largest corporate Bitcoin treasuries, and additional buying would extend a strategy that has tied the company’s market performance closely to the cryptocurrency’s price.