Microsoft Corp. (MSFT  ) has spent the past two years positioning itself as one of artificial intelligence's biggest builders. But during its fiscal fourth-quarter earnings report, the company revealed that simply investing in AI proved lucrative enough to outperform one of its own operating businesses. Chief Financial Officer Amy Hood disclosed that Microsoft recorded a $3.2 billion gain from its investment in Anthropic during the quarter. The windfall was so large that it exceeded the $2.748 billion of operating income generated by Microsoft's entire More Personal Computing segment, which includes Windows, devices, Xbox and search advertising, by about 16%.

Anthropic Delivers A Bigger Profit Than Windows, Xbox Segment

The gain wasn't part of Microsoft's core operations. Instead, Hood listed it among the items that boosted quarterly earnings beyond the company's previous guidance.

"These included a $3.2 billion gain from our investment in Anthropic and lower than expected expenses related to the voluntary retirement program, which were partially offset by severance expense and impairment charges in Xbox," Hood said during the earnings call.

By comparison, Microsoft's More Personal Computing division generated $12.85 billion in quarterly revenue but just $2.748 billion in operating income, as weakness in Windows OEM and Xbox continued to weigh on profitability.

The segment remains one of Microsoft's three reporting divisions, housing products including Windows, Surface devices, Xbox gaming and Bing search.

Microsoft's AI Strategy Extends Beyond OpenAI

The Anthropic gain also highlights how Microsoft's AI strategy has expanded well beyond its closely watched partnership with OpenAI.

While OpenAI remains central to Microsoft's AI ambitions, CEO Satya Nadella repeatedly emphasized that the company is building an AI platform designed to support multiple frontier model providers.

"We offer the broadest model catalog in the cloud with over 11,000 models, including the latest from OpenAI, Anthropic, Mistral, xAI, as well as our own MAI family," Nadella said.

Microsoft also disclosed that customers are increasingly embracing that approach.

"Since the start of the year, we have seen 5x increase in the number of customers building with models from multiple providers," Nadella said, citing Levi Strauss & Co (LEVI  ) as one enterprise customer using both OpenAI and Anthropic models through Microsoft's Foundry platform.

AI Investments Continue To Pay Off

The Anthropic gain arrived alongside another strong quarter for Microsoft's AI business.

Azure and other cloud services revenue climbed 43% year over year, helping Microsoft Cloud revenue surpass $214.4 billion for the fiscal year. Commercial remaining performance obligations rose to $678 billion, reflecting continued demand for Microsoft's cloud and AI offerings.

During the call, Nadella also reiterated that Microsoft is designing its AI infrastructure so enterprises are not locked into any single model provider.

"It also has the added benefit of business continuity and resilience because every model is substitutable," he said while describing Microsoft's multi-model AI architecture.

For investors, the quarter underscored an increasingly diversified AI strategy. Microsoft isn't just generating revenue by selling AI infrastructure and software-it is also benefiting financially from investments in companies helping shape the next generation of artificial intelligence.