Microsoft's Satya Nadella and OpenAI's Sam Altman, key figures in AI investment, in a strategic meeting.

Editorial illustration for Microsoft marks down OpenAI investment by USD 600 million

Microsoft marks down OpenAI investment by USD 600 million

By AI Daily Post Edited by Brian Petersen, Editor-in-Chief

July 30, 2026 • 3 min read

Microsoft's fiscal fourth-quarter earnings report, covering the period ending June 30, came with a rare side-by-side look at how its two big AI bets are performing. The company logged a $3.2 billion gain on its Anthropic stake, adding 33 cents to diluted earnings per share, which landed at $4.81 for the quarter. That investment traces back to a $5 billion deal struck in November 2025, part of an arrangement where Anthropic also committed to buying $30 billion in Azure services. Microsoft doesn't typically revalue that stake every quarter, but it made an exception this time.

OpenAI told a different story. Microsoft owns roughly 27% of the company and reports the value of that stake each quarter, separate from whatever revenue-share payments flow in under their commercial agreement, figures the company doesn't disclose. This time around, the OpenAI position moved in the wrong direction, and Microsoft had to account for it on the books.

The overall quarter was still enormous by any measure, with $90 billion in revenue and $35.8 billion in net income. Against numbers like that, the OpenAI markdown barely registers.

For the year, Microsoft’s OpenAI investment generated a $5 billion gain and added $0.67 on EPS, respectively, the company reported. (Microsoft reported $17.95 EPS for its fiscal year.) Still, it is noteworthy that Microsoft reported nearly as much of a gain on Anthropic in one quarter as it did for the year on OpenAI for the entire year.

Microsoft logs $3.2B from Anthropic investment, but OpenAI was a mixed bag - TechCrunch AI

Why this matters

Microsoft's earnings footnote is the first hard number we've gotten on how the company itself values its OpenAI stake, and a $600 million markdown in a single quarter is not nothing, even against a $3.2 billion gain on Anthropic. For developers and founders building on either platform, this is a signal worth watching rather than dismissing: it suggests Microsoft's accountants see more uncertainty in OpenAI's trajectory than in Anthropic's right now, even as both remain central to Microsoft's AI strategy. The lack of disclosure on OpenAI's revenue-share payments is its own tell.

Microsoft will happily quantify the Anthropic upside but stays vague on what OpenAI actually pays back, which makes it harder for outsiders to judge whether the OpenAI relationship is still the better financial bet or just the more entrenched one. If you're deciding which model provider to build on, or negotiating your own enterprise deal with either lab, this is a reminder that the partnerships underpinning your infrastructure have their own internal scorecards, and those scorecards don't always match the marketing.