Microsoft’s fiscal 2026 Q4 earnings report, which ended June 30, was a blockbuster - $90 billion in revenue, $35.8 billion in net income, and the kind of profit that makes other companies weep into their spreadsheets. But tucked inside the fine print was a tale of two AI investments: Anthropic, the new golden child, and OpenAI, the slightly tarnished star.

For the quarter, Microsoft recorded a $3.2 billion gain on its $5 billion investment in Anthropic (made in November 2025 as part of a circular deal where Anthropic agreed to buy $30 billion worth of Azure services). That boosted diluted earnings per share by 33 cents, contributing to the $4.81 EPS. Meanwhile, Microsoft’s investment in OpenAI - of which it owns about 27% - took a $600 million write-down, shaving 7 cents off EPS. The write-down is a rounding error for a company with $90 billion in quarterly revenue, but it’s still a reminder that AI investments are not all neural network rainbows.

On a full-year basis, Microsoft’s OpenAI investment looked healthier: a $5 billion gain and $0.67 added to EPS (against $17.95 EPS for the fiscal year). Still, it’s worth noting that Microsoft reported nearly as much gain from Anthropic in one quarter as it did from OpenAI in an entire year. That’s the kind of detail that makes investors sit up and take notice - and makes Microsoft’s decision to disclose it feel like a subtle flex.