Ackman Loads $2.1B Microsoft Stake as AI Run Rate Hits $37B

Bill Ackman’s Pershing Square disclosed a 5.65 million-share Microsoft position worth $2.1 billion, funded partly by selling over 6 million Alphabet shares in a valuation rotation. The stake, started in February and revealed May 15-28, now represents about 15% of the fund. Microsoft’s fiscal Q3 results showed Azure growth at 40%, an AI annualized run rate of $37 billion, and commercial RPO surging 99% to $627 billion despite $190 billion 2026 capex guidance. Shares rose nearly 2% on Anthropic chip talks and 3% after the Ackman disclosure. Earlier, the University of Michigan’s $20 million OpenAI bet reached $2 billion.