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

When Anthropic, the artificial intelligence firm, commences trading following its anticipated IPO next week, the early share price will largely be influenced by who is compelled to purchase it, rather than who seeks to purchase it. Investors are drawing parallels between Anthropic's IPO and SpaceX's successful June debut on the stock market.

SpaceX's strategic approach to its IPO altered the playbook for listing major companies, as Nasdaq and other major US index providers revised their criteria for inclusion, creating a substantial pool of passive investment money to purchase the shares within the first 15 days of the listing. Anthropic aims to raise up to $64.4 billion by selling 825 million shares priced between $70 and $78 each, which would value the company at up to $1.4 trillion.

Similar to SpaceX, Anthropic will be incorporated into at least six major indexes within 5 to 15 days of its listing, including FTSE's USA index, the S&P Total Market Index, and the Nasdaq 100. Carsten Hesse, London-based head of index events at Berenberg, explains that index-related factors will drive the early trading dynamics for Anthropic.

London-based index rebalance analytics firm Intropic estimates that passive demand from index-tracking funds will account for approximately 28% of Anthropic's shares offered, or roughly $19 billion. Investors anticipate a similar buying pattern as with SpaceX, where index funds and retail investors flocked to purchase nearly half of the SpaceX shares during the IPO, capitalizing on the early momentum.

Analysts predict that Anthropic shares will also experience early buying, likely on the third day of trading when stock-option trading begins. Similar to SpaceX shares, Anthropic shares may see a significant increase within the first 3 days, followed by a gradual decline as investors prepare for the first wave of lock-up expirations, allowing employees and other pre-IPO backers to sell their shares.