OpenAI appears to have delivered a major hit with Astra.
OpenAI’s newest frontier model, Astra, has overtaken Anthropic’s Fable in enterprise spend, according to data shared by Ramp Chief Economist Ara Kharazian. As of this week, Astra accounts for roughly 13% of enterprise AI spend tracked by Ramp, compared to 8% for Fable — a reversal that comes just months after Fable’s own launch was supposed to cement Anthropic’s position at the frontier.
The chart Kharazian posted tells a fairly dramatic story. Fable’s share climbed steadily from July onward, spiking to nearly 10% by early September before sliding back to 8%. Astra, which sat at zero for the entire summer, shot almost vertically past Fable within the space of about two weeks once it launched in September, and shows no sign of slowing down.
Anthropic’s frontier bet
Kharazian frames this as the direct result of a strategic choice Anthropic made. In his read, Anthropic took a real risk with how it chose to pace its frontier releases, and that bet hasn’t paid off on the adoption side so far — Fable has already fallen behind on enterprise takeup despite arriving with strong benchmark claims. That’s a notable turn given how much ground Anthropic had gained in the broader enterprise race over the past year. Ramp’s own index previously showed Anthropic’s share of combined OpenAI-and-Anthropic business subscription spend climbing from roughly 10% in early 2025 to over 65% by February 2026, and Anthropic has generally been described as the enterprise favorite in software, finance, and professional services, the three highest-adoption sectors on Ramp’s data. Losing ground specifically at the frontier-model tier, where Fable was meant to be Anthropic’s showcase, cuts against that broader momentum.
Where OpenAI’s gains are coming from
The second point Kharazian raises is about the composition of Astra’s growth. According to his analysis, OpenAI’s gains are coming primarily from businesses shifting spend away from its own older Sol model and from some Anthropic customers, alongside genuinely new usage. He reads that mix as a good sign for OpenAI specifically because it suggests the company retains real pricing power whenever it has a frontier model that’s competitive on merit, rather than growth that’s purely a function of discounting.
That reading lines up with a wider pattern in the OpenAI-Anthropic rivalry this year, where the two companies have repeatedly traded leads depending on which slice of spend is being measured. Ramp’s broader monthly index has shown Anthropic pulling further ahead on overall business adoption as recently as July, even as this narrower frontier-model comparison now favors OpenAI. And the flip isn’t confined to enterprise card spend — it also showed up in OpenRouter’s own wallet-share data, where OpenAI models pulled ahead of Anthropic’s for the first time in two and a half years in the same stretch of September.
Taken together, the picture is one of a rivalry that’s being fought on several fronts at once — API tokens, enterprise subscriptions, and now frontier-model mindshare specifically — with no single dataset telling the whole story. Astra’s early lead over Fable is the latest data point, and whether it holds will depend on whether Anthropic answers with a Fable update of its own, or whether OpenAI’s frontier model keeps pulling in switchers from both Sol and Claude.