MicroStrategy has expanded its Bitcoin holdings by acquiring 15,000 BTC for $1.5 billion, raising its total to 438,650 BTC valued at approximately $45.6 billion. The company has invested $27.1 billion in Bitcoin at an average price of $61,725 per BTC, with recent purchases funded through a share sale program and convertible notes. This announcement coincides with MicroStrategy's inclusion in the Nasdaq-100 index, effective December 23, and follows significant fluctuations in Bitcoin's value, which recently stabilized around $104,000.