SpaceX, OpenAI, Anthropic: The AI Mega‑IPO Trio Set to Reshape the S&P 500

Three mega IPOs — SpaceX, OpenAI and Anthropic — could materially reshape the S&P 500 over the next two years by adding unprecedented large-cap technology and AI businesses to the index. SpaceX is highlighted as the biggest potential market-cap mover (estimated $1.75–$2.0 trillion at debut, driven by Starlink and other assets), while OpenAI plans significant retail allocations and Anthropic is noted for more digestible financials and recent product advances. Inclusion rules mean each firm would likely sit out about a year before S&P membership, but their eventual listings and valuations could alter index composition, sector weightings and market leadership amid the ongoing AI boom.