AI firm Anthropic is to float in a $1.5 trillion share sale, with up to a fifth reserved for private investors

Anthropic, the Claude AI company founded just five years ago by Dario Amodei and his sister Daniella, is planning to float within weeks in what analysts describe as a flotation of 'monumental importance' to global stock markets. The IPO could eclipse even this summer's $1.3 trillion SpaceX listing. Chief executive Dario Amodei and Daniella, the firm's president, are each set to hold a $13 billion fortune after the deal closes.

Up to 20 per cent of shares are earmarked for private investors, opening the offering beyond institutional buyers.