A media report attributed the gap to investors' efforts to compare OpenAI with Anthropic, which uses a different revenue calculation.
OpenAI's September revenue run rate below earlier estimate, source says
Investors were told annualized revenue was almost $50 billion, rather than the previously indicated level approaching $70 billion.

The September revenue run rate OpenAI communicated to investors was almost $50 billion on an annualized basis, a person with knowledge of the matter said on October 8. The figure was lower than an earlier indication from the company.
Media reports said OpenAI had put the September run rate at approaching $70 billion during another investor event. The person, who spoke anonymously, attributed most of the discrepancy to an effort to compare OpenAI's figures directly with those of competitor Anthropic. OpenAI did not provide a response when asked for comment.
The two companies account for revenue differently. OpenAI leaves out sales made through cloud partners, including Amazon's AWS and Alphabet's Google Cloud, while Anthropic includes them.
At the start of the year, OpenAI's annualized revenue stood at $20 billion, up from $6 billion in 2024. Anthropic moved ahead on quarterly revenue for the first time during the second quarter: it reported $11.5 billion, while OpenAI reported $6.7 billion. Both companies are making preparations to go public.
A revenue run rate commonly takes sales from one month and multiplies that amount by 12. Analysts view the measure as potentially misleading, though rapidly growing startups in Silicon Valley frequently use it.
