When Microsoft reported excellent earnings in the fourth quarter of its fiscal 2026 year (which ended June 30), it included an interesting little tidbit about how its investments in the two largest and competing AI labs are faring.

For the quarter, it recorded its investment in Anthropic as a gain of $3.2 billion, increasing diluted earnings per share by 33 cents. (Microsoft reported diluted earnings per share of $4.81 for the quarter.) Microsoft invested $5 billion in Anthropic in November 2025 as part of a circular deal under which the AI ​​lab also agreed to purchase $30 billion worth of Azure services.

Microsoft does not regularly update the value of its investment in Anthropic each quarter. However, it analyzes its investment in OpenAI on a quarterly basis. Microsoft said investment didn’t fare as well in the quarter and cut it by about $600 million, reducing diluted earnings per share by about 7 cents per share.

Microsoft owns about 27% of OpenAI. And while Microsoft also receives revenue-sharing payments, it doesn’t disclose how much OpenAI pays under that deal. Instead, Microsoft represents the value of your investment. While this quarter brought a fairly sizable decline in the value of that investment, the $600 million writedown was still primarily a rounding error for Microsoft. The company had a highly profitable quarter, reporting $90 billion in revenue and net income of $35.8 billion for the quarter. Microsoft’s revenue was $331.8 billion with net income of $133.7 billion for the year.

Microsoft’s investment in OpenAI looks much better when looking at the full year.

During the year, Microsoft’s OpenAI investment generated a profit of $5 billion and added $0.67 to earnings per share, respectively, the company reported. (Microsoft reported earnings per share of $17.95 for its fiscal year.) Still, it’s worth noting that Microsoft reported almost as big a profit on Anthropic in one quarter as it did on the year at OpenAI. In fact, it’s so notable that Microsoft revealed it.