According to the Ramp AI Index, which tracks corporate spending, Anthropic's adoption grew by 1.1 percentage points over the previous month, while OpenAI rose only 0.23 points to a 39.7% share.
During the same period, xAI saw its fastest growth in a year, capturing 4% of the market as businesses diversified their use of different providers.
These shifts occur as corporate customers begin to hit spending limits on AI, questioning whether the highest-performing models justify their costs.
Ramp reports that Anthropic’s recently released Fable 5 model—described as the most capable on the market—accounted for only 6% of purchased tokens, the basic units of text processed by AI.
At roughly $10 per million tokens, Fable 5 is twice as expensive as OpenAI’s GPT-5.6 Sol, suggesting that businesses are prioritizing cost-effectiveness over marginal gains in raw performance.
The competitive landscape is further tightening as open-source alternatives, which provide public access to their underlying code, rapidly close the capability gap with proprietary models.
Ramp’s data indicates that 6.1% of AI-using businesses are now utilizing model-serving platforms to access these open-source or specialized international models.
To maintain growth, developers must now demonstrate significant breakthroughs that competitors cannot easily replicate while managing the high costs required to stay ahead.