Bill Ackman discloses new $2.09 billion stake in megacap tech stock

Hedge fund manager Bill Ackman’s Pershing Square disclosed a new roughly $2.09 billion position in Microsoft in its Q1 2026 13F filing, a stake of about 5.65 million shares accumulated since February. The position had appreciated to about $2.3 billion by the close on May 15, and Microsoft shares rose in early trading on the disclosure. Ackman framed the entry as made at ~21x forward earnings, arguing the market has underappreciated long-term revenue upside from Azure, M365 Copilot ($30/user/month) and Microsoft’s OpenAI linkage amid near-term AI-related spending. The filing also showed Pershing Square exiting Hilton and materially reducing its Alphabet stake, signaling a rotation into what Ackman views as a core AI-infrastructure holding. The disclosure is a bullish signal for Microsoft and may validate value-oriented and institutional buying in megacap AI-linked names, with future earnings and Azure adoption critical to the thesis.