Ackman's Big Bet on Microsoft: Is the AI Play Still Worth It?

Billionaire investor Bill Ackman's Pershing Square Capital Management has a significant stake in Microsoft, with around 15% of their portfolio invested in the company.

Ackman believes that Microsoft's AI strategy and capital spending will pay off over the next decade, and he's betting big on it.

He began buying Microsoft shares in February 2026, after the stock sold off following its fiscal second-quarter report and amid concerns about cloud growth and heavy capital expenditure plans.

Ackman estimates that Microsoft's 27% stake in OpenAI could be worth around $200 billion, or 7% of Microsoft's market cap, if it were valued independently.

While Ackman is confident in his investment thesis, investors should exercise caution and not treat his enthusiasm as a blanket 'buy no matter what' endorsement. The same factors that make Microsoft attractive also create risk, including intense competition in AI infrastructure and the potential for AI demand or pricing to fall short of expectations.