The hazy OpenAI growth metric driving Wall Street

Volatility in US stocks this week, triggered by the revelation that OpenAI’s annualised revenue was about $20bn less than previously reported, has exposed the reliance of markets on a vague metric used by AI start-ups to express their growth to investors.

The FT reported on Thursday that OpenAI’s annualised net revenue was close to $50bn, a figure the company recently shared with investors as part of a fundraising effort. That is about $20bn less than the roughly $70bn first reported by Axios and later by other media outlets including the FT in late September.

In the September article, the FT reported OpenAI’s annualised net revenue was about $70bn after the company confirmed the figure was correct.

The discrepancy and the subsequent market fallout has cast a spotlight on annualised revenue, a hazy figure used by fast-growing start-ups to help investors understand their financial trajectory. The focus on the metric has renewed calls for OpenAI and its rival Anthropic to become public companies or formalise their financial reporting.

That is because publicly traded US companies must regularly disclose their performance in a standardised format to the public.

OpenAI and Anthropic are in a fierce competition to develop better AI models, and their revenue projections have become a closely watched barometer for investors and the public attempting to gauge the strength of the AI boom.

Although neither company’s stock trades publicly, shares in companies linked to AI, including Oracle and Nvidia, declined sharply on Thursday after the FT’s report on the revenue discrepancy. The AI sell-off pushed the tech-focused Nasdaq 100 down 1.4 per cent on Thursday, with the index partially recovering on Friday.

Despite investors’ focus on them, annualised revenue figures are partial, extrapolating recent performance and expectations about the sustainability of customer contracts. Adding to the confusion is the fact that OpenAI and Anthropic use different accounting methodologies to calculate their annualised revenue.

Anthropic recognises gross revenue on sales through cloud partners. That is because Anthropic is the principal in the transaction, according to a person with knowledge of its accounting practices. The Claude maker’s revenue run rate was calculated by annualising the prior 28 days of consumption-based revenue, plus recurring monthly subscription revenue, they added.

OpenAI, meanwhile, counts only its own cut of proceeds from arrangements with partners such as Microsoft.

The $70bn figure reported in September arose from attempts by investors to compare Anthropic and OpenAI performance on a like-for-like basis, according to a person close to OpenAI. However, OpenAI described the $70bn as a “net” revenue metric when it was approached by the FT at that time.

OpenAI has always used the net figure in its internal accounting, and even on a gross basis the $70bn estimate would be inaccurate, the person close to the company said.

In a statement, OpenAI said: “Last week, we shared remarkable 70 per cent growth in annualised run rate revenue in Q3. Subsequent reports that we had reached $70bn run rate were not accurate. We can confirm our current run rate is approximately $50bn.”

Wall Street’s sensitivity to the revenue figures underscores how important OpenAI and Anthropic are to the broader AI boom, which has sent US stocks to record highs and helped fuel economic growth.

Annualised figures provide private market investors with a sense of a start-up’s momentum — typically more important to venture capitalists than profitability. But OpenAI and Anthropic have reached an unprecedented scale and significance for such young, unlisted companies that they both face calls to go public or provide more detailed accounts of their performance.

Anthropic is expected to do so later in 2026, while OpenAI has deferred its listing to next year.

OpenAI’s business performance has taken off in recent months since the release of the company’s GPT-5.6 model in July. The company told prospective investors in an upcoming funding round that it had revised up its estimated full-year revenue for 2026 to $35bn from $30bn it had forecast in the first quarter.