Ramp's latest data reveals OpenAI is regaining ground against Anthropic in the U.S. corporate AI market. While Anthropic briefly led with a 41% share in May, OpenAI has since closed the gap to nearly 40% by July, according to analysis of over 70,000 businesses using Ramp's services. The report highlights that OpenAI's Q3 growth rate surpasses Anthropic's among tech industry clients, though market dynamics remain volatile. Factors like model performance and regulatory constraints influence adoption rates. OpenAI's GPT-5.6 Sol is gaining traction among developers, while Anthropic's Fable 5 faces challenges due to pricing and data retention requirements. Despite competition, the overall AI market is expanding, with over 56% of Ramp clients now paying for AI tools. The report underscores the fluid nature of enterprise AI spending, raising questions about long-term investment stability for both companies.