Microsoft's Anthropic Bet Just Paid Off Bigger Than OpenAI During FY26 Q4

Microsoft’s latest earnings report wasn’t just about Azure, Windows, or AI revenue. Hidden inside the numbers was a surprising twist that showed two of the company’s biggest AI investments moving in completely different directions.

Anthropic delivered one of Microsoft’s biggest quarterly gains

Microsoft reported a $3.2 billion gain from its investment in Anthropic during the fourth quarter of fiscal 2026. The company said the gain added 33 cents to its diluted earnings per share, making it one of the more notable highlights buried inside the earnings report.

The software giant invested $5 billion in Anthropic last November. The deal also included Anthropic committing to purchase $30 billion worth of Azure cloud services over multiple years, strengthening Microsoft’s cloud business alongside its AI ambitions.

That being said, Microsoft does not revalue its Anthropic investment every quarter. This makes the latest update particularly notable since the company rarely discloses changes tied to that stake.

OpenAI followed a different path this quarter

While Anthropic boosted Microsoft’s results, OpenAI moved the opposite way. Microsoft recorded a $600 million write-down on its investment, reducing diluted earnings per share by roughly 7 cents during the same quarter.

The decline barely dented Microsoft’s overall performance. The company still reported $90 billion in quarterly revenue and $35.8 billion in net income, supported by continued growth across Azure and enterprise software.

Speaking of OpenAI, the longer-term picture remains much stronger. Microsoft’s investment generated a $5 billion gain over the full fiscal year and contributed 67 cents to annual earnings per share. Microsoft currently owns about 27% of OpenAI, although it does not disclose how much revenue it receives through the companies’ separate commercial agreements.