Microsoft’s shareholder base shifted sharply in the first quarter, underscoring a growing divide over how to value the company’s AI push. New 13F filings show Bill Ackman’s Pershing Square built a fresh stake, the Bill & Melinda Gates Foundation Trust sold its remaining shares, and TCI Fund Management cut its position dramatically. The moves came as Microsoft stock fell more than 15% this year, leaving the shares near $410 and the company facing tougher questions about whether heavy AI spending will pay off quickly enough.
Ackman disclosed that Pershing Square began buying Microsoft in February and had accumulated 5.6 million shares by mid-May, worth about $2.3 billion at current prices. He said the firm bought the stock at roughly 21 times forward earnings, close to the broader market and below Microsoft’s recent historical average. His argument is straightforward: the market is treating Microsoft’s planned $190 billion in 2026 capital spending as a margin risk, while he sees it as an investment cycle that should produce stronger returns later.
By contrast, the Gates Foundation Trust fully exited Microsoft in the quarter, selling its final 7.7 million shares, now worth roughly $3.2 billion. The sale is notable because the foundation’s endowment was built in large part from Microsoft stock donated by Bill Gates and Melinda French Gates. Still, the move appears more tied to the foundation’s long-term spending plans than to a fresh judgment on Microsoft’s business. Gates has said the foundation will distribute its assets over time, and the trust had already been reducing its Microsoft exposure through 2025.
TCI’s retreat was more clearly a portfolio call. The London-based hedge fund run by Christopher Hohn reduced its Microsoft holding by about 83%, cutting the position from around 10% of assets at the end of 2025 to roughly 1% by March. According to reports, TCI has grown more concerned that rapid advances in AI could disrupt parts of Microsoft’s traditional software franchise. At the same time, it increased its Alphabet stake, suggesting it sees a better risk-reward balance elsewhere in big tech.
The split among these investors reflects the central question hanging over Microsoft this year. The company is still delivering solid operating results: recent quarterly revenue rose 14% from a year earlier, Azure growth remained strong at 36%, and earnings beat Wall Street expectations. But those numbers are being weighed against the scale of the AI buildout and management’s warning that spending will pressure margins in the near term.
That tension is especially important as Microsoft shifts parts of its AI business toward usage-based pricing through products such as Copilot and GitHub. Investors are being asked to fund infrastructure now while waiting for a clearer picture of long-term monetization. For some, that creates an opening. For others, it raises the risk that returns arrive later than expected or fall short of the cost.
What the latest filings make clear is that Microsoft has become one of the market’s cleanest tests of AI conviction. Ackman is betting the recent selloff has created a rare entry point into a dominant platform company. TCI is signaling that even top-tier software businesses are not immune to disruption during a technology transition. The Gates Foundation’s exit removes a historically symbolic holder, even if the decision was largely structural. The next few quarters should show whether Microsoft’s spending surge strengthens its lead or keeps the stock under pressure.