OpenAI said to prepare confidential S-1 for a 2027 IPO; valuation reports range far below the ~$1tn headline figures

OpenAI is preparing to confidentially file a draft registration statement (Form S-1) with the SEC and is targeting a public listing as soon as September 2026, according to reporting by CNBC and Axios and aggregated by TechTimes. The valuation target cited by the primary reporting ranges between roughly $730 billion and $850 billion; OpenAI's last private mark was about $852 billion post-money following a record $122 billion funding round closed March 31, 2026. Goldman Sachs and Morgan Stanley are reported as lead underwriters.

Coverage cites an annualized revenue run-rate around $25 billion (roughly $2 billion per month) reached by March 2026, with tens of millions of consumer subscribers and millions of business users, but also heavy losses — one widely cited figure was a loss of about $1.22 for every $1 of revenue in Q1 2026. A confidential filing keeps audited financials and full risk disclosures private during SEC review. The OpenAI step, alongside Anthropic's June 1 confidential S-1, frames a closely watched 'race' between the two largest frontier-AI labs to test public markets, arriving in the same window as the Cerebras debut and SpaceX mega-IPO.

IMPORTANT CAVEAT: the strongest contemporaneous mainstream reporting frames OpenAI as 'preparing to' confidentially file rather than confirming a completed S-1; precise figures vary across secondary outlets and OpenAI has not published a prospectus or confirmed terms. The exact filing date, valuation band and timetable are unverified. Treated as developing pending a public S-1 or company confirmation.