During its fiscal 2026 fourth quarter, Microsoft reported exceptional overall earnings whilst revealing divergent performance from its two major AI investments. The technology giant recognised a $3.2 billion gain on its Anthropic stake, which it acquired for $5 billion in November 2025 under an arrangement where Anthropic committed to purchasing $30 billion in Azure services. This single quarter's appreciation added meaningfully to results, boosting diluted earnings per share by 33 cents and representing substantial value growth in the younger AI lab.

Microsoft's established OpenAI investment, which the company revalues quarterly, moved in the opposite direction during the period, declining roughly $600 million and reducing earnings by 7 cents per share. Viewed annually, the OpenAI stake recovered to generate a $5 billion gain for the full year. However, the emergence of nearly equivalent single-quarter Anthropic gains relative to full-year OpenAI performance struck Microsoft as significant enough to explicitly highlight, suggesting a notable recalibration in how the company's AI portfolio valuations are evolving.