For a few months now, the gap between OpenAI and its closest rival Anthropic has been narrowing faster than most investors anticipated, and the numbers are starting to make some of OpenAI's own backers uncomfortable. According to reporting by the Financial Times, a portion of OpenAI's investor base is quietly questioning whether the company's $852 billion valuation is still defensible, particularly as Anthropic continues to post the kind of revenue growth that is difficult to ignore.
For a few months now, the gap between OpenAI and its closest rival Anthropic has been narrowing faster than most investors anticipated, and the numbers are starting to make some of OpenAI's own backers uncomfortable. According to reporting by the Financial Times, a portion of OpenAI's investor base is quietly questioning whether the company's $852 billion valuation is still defensible, particularly as Anthropic continues to post the kind of revenue growth that is difficult to ignore.
Anthropic's annualized revenue jumped from $9 billion at the end of 2025 to $30 billion by the end of March 2026, driven largely by demand for its coding tools. That trajectory, compressed into a single quarter, has shifted how some investors are weighing the two companies against each other. One investor who has backed both companies told the Financial Times that justifying OpenAI's round required assuming an IPO valuation of $1.2 trillion or more, making Anthropic's current $380 billion valuation look like the relative bargain.
The secondary market is reflecting that sentiment in real time. Anthropic shares are in high demand while OpenAI shares are trading at a discount. On Caplight, a secondary trading platform, Anthropic's valuation has reached $688 billion, up 75 percent from three months ago. That kind of appreciation in private market demand is a meaningful indicator of where sophisticated capital is leaning right now.
The strategic picture at OpenAI has not helped build confidence either. Some backers say OpenAI has revised its product roadmap twice in six months and risks losing focus ahead of an IPO expected as early as Q4 2026. The pivots, first in response to pressure from Google and then from Anthropic, have raised questions about whether the company has a settled sense of where it is going. Anthropic has made significant gains in enterprise, with its share of US enterprise AI spending climbing to 40 percent while OpenAI's fell from 50 to 27 percent over the same period.
OpenAI has pushed back on the narrative firmly. Chief financial officer Sarah Friar pointed to the $122 billion fundraise completed last month, described as the largest private round in Silicon Valley history and backed by SoftBank, Amazon, Nvidia, Andreessen Horowitz, Sequoia Capital, and Thrive Capital among more than 25 investors, as evidence of continued confidence. The company has also moved to reframe the compute conversation, arguing it holds a structural infrastructure advantage over Anthropic. OpenAI told investors it foresees its own footprint climbing into the low-double-digit range of gigawatts within a year and hitting 30 gigawatts by 2030, and that Anthropic would top out somewhere between seven and eight gigawatts before the close of 2027.
The accounting question has also entered the conversation. OpenAI's new chief revenue officer accused Anthropic of overstating its run rate by roughly $8 billion, with the dispute turning on a well-documented accounting difference: Anthropic books the full value of revenue generated through its cloud distribution partners, while OpenAI uses the net method. Both companies say they follow standard accounting practices, but the disagreement adds a layer of complexity to any direct revenue comparison.
Iconiq Capital partner Roy Luo, whose firm has committed over $1 billion to Anthropic while maintaining a smaller OpenAI stake, told the Financial Times there is room for both companies, but that the market leader will win disproportionately and his firm has made its choice. That kind of direct statement from a major institutional backer captures the mood well. Investors are not necessarily writing OpenAI off, but they are recalibrating, and Anthropic's momentum has made that recalibration feel urgent.
