Investors Built $70B OpenAI Revenue Estimate Using Wrong Method; AI Stocks Fell When FT Corrected

A bookkeeping rule buried in US generally accepted accounting principles — one that governs whether a company records a transaction at its full value or only its retained share — produced a $20 billion discrepancy in OpenAI's reported revenue and triggered a broad selloff across AI-adjacent equities Thursday.The Financial Times reported Thursday that OpenAI's actual annualized revenue run rate approached $50 billion at the end of September 2026 — a figure $20 billion below the $70 billion estimate that had circulated among investors and driven a fresh wave of AI market optimism. Nvidia fell nearly 3 percent, Oracle shed close to 6 percent, and Arm Holdings dropped more than 6 percent on the news.The gap was not the product of fraud, aggressive accounting, or company misdirection.