What would the S&P looks like with SpaceX, OpenAI and Anthropic?

The article models a hypothetical inclusion of SpaceX, OpenAI and Anthropic into the S&P 500 and quantifies the index and market-structure impact. The three mega-IPOs would add about $3.13 trillion to the benchmark, lifting the S&P 500’s market cap to roughly $60.3 trillion and making the newcomers ~5.2% of the index. Their addition would push top-10 concentration above 40%, increasing crowding and AI-theme reliance. With assumed public floats of 15%–25%, bringing them public would require roughly $432 billion–$576 billion in capital absorption, posing significant liquidity and scale challenges for IPO markets and index inclusion processes.