OpenAI, Anthropic and SpaceX megacap IPO wave could add about 5% to global equity value

OpenAI, Anthropic and SpaceX are expected to pursue IPOs within months, together potentially adding about 5% to the stock market’s total capitalisation. JP Morgan estimates roughly $410bn of passive buying tied to their index inclusion, a shift that would reduce weights for incumbents including the S&P 500’s “Mag 7”. With the top 10 S&P 500 companies already accounting for more than 40% of the index, additional AI listings could lift concentration toward levels last seen around 1932 and just before the early-2000s dotcom bust.