Ackman’s Pershing Square Builds Microsoft Stake on AI Optimism
Bill Ackman just bet big on Microsoft's AI upside. Here's why a $0B+ stake matters for the Copilot narrative.

Why it matters
Major institutional investor Pershing Square is signaling confidence in Microsoft's AI monetization strategy and Copilot adoption, despite a 15% YTD stock decline. This is a strategic vote of confidence in enterprise AI ROI from a prominent activist investor.
The key facts
10 to knowPershing Square Capital Management (Bill Ackman) built new stake in Microsoft
Microsoft stock down ~15% YTD as of May 2026
Ackman's thesis: investors underestimating Office 365 resilience and Copilot AI growth
Announced via X post (May 15, 2026)
Position driven by AI optimism narrative, not traditional enterprise software thesis
Pershing Square Capital built stake in Microsoft
Microsoft stock down ~15% YTD (as of May 2026)
Ackman thesis: market underestimates Office 365 resilience and Copilot growth
Copilot positioned as key growth driver
Activist investor vote of confidence in enterprise AI adoption
Go to the source
The Informationtheinformation.com
Publisher excerpt: Bill Ackman’s Pershing Square has bought a stake in Microsoft, Ackman said in a post on X Friday, arguing that the company’s nearly 15% share slide so far this year has been driven by investors who “underestimate the resilience” of its Office 365 software and growth of its newer Copilot AI ...