Tom Lee: Trillions in SpaceX, OpenAI, and Anthropic IPO Supply Won't Sink the S&P 500

Fundstrat's Tom Lee is pushing back on fears that a historic wave of mega-IPOs could destabilize public markets. SpaceX, OpenAI, and Anthropic are all reportedly eyeing U.S. listings, and Lee estimates the combined post-lockup supply could equal 5% to 6% of the S&P 500's total market cap — a scale that would dwarf the entire dot-com IPO boom in inflation-adjusted terms. SpaceX alone, targeting a valuation above $1.5 trillion, could rank as the second-largest IPO in history behind only Saudi Aramco.

Lee's counterargument rests on demand, not supply. Family offices, pensions, and high-net-worth investors have spent years underallocated to public equities in favor of private markets and alternatives. That capital, he argues, is available to rotate back in and absorb the new float — and many early holders will hedge or borrow against positions rather than sell and trigger large tax…