OpenAI Files for IPO Just Days After Anthropic — The AI Arms Race Is Now a Wall Street Arms Race

OpenAI filed a confidential S-1 registration statement with the US Securities and Exchange Commission (SEC) on Monday, just a week after rival Anthropic filed for its own initial public offering (IPO), turning the race to build artificial intelligence into a battle for Wall Street capital.

The ChatGPT maker, valued at $852 billion (£638 billion) after a record $122 billion (£91.3 billion) funding round in March, set no listing date or share price. 'We expect it to leak, so we're just announcing it,' the company said in a blog post. Goldman Sachs and Morgan Stanley are leading the deal, with a listing possible as early as autumn.

Anthropic filed its own confidential prospectus on 1 June at a $965 billion (£723 billion) valuation. SpaceX is set to debut on the Nasdaq on 12 June. Three blockbuster AI-adjacent listings in a fortnight will force investors to choose where their money goes.

Why the Race to List First Matters

The timing is no accident. Whoever goes public first will set the valuation benchmark for the entire AI sector, and the next company to market will be priced against those terms.

A PitchBook report described OpenAI as overvalued relative to its fundamentals, and Anthropic's disclosures will give investors a direct comparison when OpenAI prices its offering. With institutional capital spreading across multiple listings, the first company to debut will absorb a large share before the others even ring the bell.

A Growth Story With Missing Chapters

OpenAI is racing to Wall Street while grappling with questions about its own trajectory. The Wall Street Journal reported in April that the company missed several internal monthly revenue targets in early 2026 and fell short of its goal of one billion weekly active ChatGPT users by the end of 2025. Anthropic has gained ground among enterprise and coding customers.

OpenAI expects to burn $85 billion (£64 billion) in 2028 even after doubling revenue, the Wall Street Journal reported. The company does not expect positive cash flow until 2030. ChatGPT now has more than 900 million weekly active users, but Chief Financial Officer Sarah Friar has privately raised concerns about whether revenue growth can keep pace with infrastructure costs.

Legal Hurdle Cleared, Financial Questions Linger

The filing came weeks after OpenAI cleared its last legal obstacle. On 18 May, a federal jury unanimously dismissed co-founder Elon Musk's lawsuit against the company and CEO Sam Altman, ruling that no binding 'founding agreement' had ever been established. Musk had sought $150 billion (£112 billion) in damages and Altman's removal.

Microsoft holds a 27% stake valued at $135 billion (£101 billion) in OpenAI Group PBC, the public benefit corporation formed during the company's October 2025 restructuring. The software giant stands to gain from a strong debut, but the gap between OpenAI's $852 billion valuation and Anthropic's $965 billion figure raises questions about whether the market is pricing in hope rather than performance.

Ready or Running Out of Runway

OpenAI's own words hinted at the tension. 'It may be a while because there are things we want to do that are likely easier as a private company,' the blog post read. That caution sits uncomfortably next to the urgency of filing just a week behind a rival valued $113 billion (£85 billion) higher.

If OpenAI's stock soars after listing, it will validate the AI spending boom and pull more investment into the sector. If it stumbles, it could cool the gold rush and ripple through every industry betting on AI transformation. The question isn't whether to watch this IPO. It's whether OpenAI is going public because it is ready or because it needs the money.