Markets & Business
Microsoft books $3.2B Anthropic gain, marks down OpenAI stake
Microsoft recorded a $3.2 billion gain on its Anthropic investment this quarter, adding 33 cents to earnings per share, while marking down its OpenAI investment by about $600 million.
Microsoft’s fiscal 2026 fourth-quarter earnings, covering the period through June 30, included a notable detail about how its investments in the two largest competing AI labs are performing. The company recorded its stake in Anthropic as a $3.2 billion gain for the quarter, boosting diluted earnings per share by 33 cents; Microsoft reported diluted EPS of $4.81 for the quarter overall. Microsoft invested $5 billion in Anthropic in November 2025 as part of a circular agreement under which Anthropic also agreed to buy $30 billion worth of Azure services.
Microsoft does not routinely update the value of its Anthropic investment each quarter, but it does discuss its OpenAI investment quarterly. That investment fared less well this quarter: Microsoft marked it down by about $600 million, reducing diluted EPS by roughly 7 cents. Microsoft owns about 27% of OpenAI, and while it also receives revenue-share payments from the arrangement, it does not report how much OpenAI pays under that agreement — instead, it accounts for the value of the investment itself. The $600 million write-down was still mostly a rounding error against a highly profitable quarter, in which Microsoft reported $90 billion in revenue and net income of $35.8 billion. For the full fiscal year, Microsoft’s revenue was $331.8 billion and net income was $133.7 billion.
Viewed over the full year rather than the quarter, Microsoft’s OpenAI investment looks considerably better: it generated a $5 billion gain and added $0.67 to full-year EPS, on total reported EPS of $17.95 for the fiscal year. Still, it’s notable that Microsoft booked nearly as large a gain on Anthropic in a single quarter as it did on OpenAI across the entire year — notable enough that Microsoft disclosed it.
Why it matters
The disclosure gives investors a rare side-by-side read on how Microsoft’s stakes in the two rival AI labs are performing, and shows how a single quarter’s investment gain can rival a full year’s worth of returns from the older, larger position.