OpenAI, Anthropic, SpaceX and Stripe are rumoured to be among ten of the biggest companies considering IPOs OpenAI, Anthropic, SpaceX and Stripe are rumoured to be among ten of the biggest companies considering IPOs Y ou’ve probably heard of “unicorns” – technology startups valued at more than $1bn – but 2026 is shaping up to be the year of the “ hectocorn ”, with several US and European companies potentially floating on stock markets at valuations over $100bn (£75bn). OpenAI, Anthropic, SpaceX