From SpaceX to Anthropic, markets have a new playbook for mega-share debuts

What happened: Anthropic aims to raise up to $64.4 billion in an IPO, and like SpaceX it will be added to at least six big indexes within 5 to 15 days of listing under new index rules. Key numbers: 825 million shares priced at $70 to $78 each; valuation up to $1.4 trillion; passive demand about Why it matters: Analysts say early buying is driven by expected index inclusion and passive demand, with index-rebalancing funds and hedge funds pre-positioning. Berenberg's Carsten Hesse called Anthropic a mirror image of the SpaceX IPO with the same index-related drivers over the first 15 days.

Anthropic aims to raise up to $64.4 billion in an IPO, and like SpaceX it will be added to at least six big indexes within 5 to 15 days of listing under new index rules.

Analysts say early buying is driven by expected index inclusion and passive demand, with index-rebalancing funds and hedge funds pre-positioning. Berenberg's Carsten Hesse called Anthropic a mirror image of the SpaceX IPO with the same index-related drivers over the first 15 days.