Three companies — SpaceX, OpenAI, and Anthropic — are expected to go public in mega-IPOs in the second half of 2026. The posited numbers are simply staggering compared to the largest IPOs in recent history, as the following figure shows.
In inflation-adjusted terms, SpaceX alone would rank as the second-largest IPO in history, just behind Saudi Aramco. All three together would exceed the entire dot-com IPO wave of 1995–2000. They will be at least half the value, inflation-adjusted, of all US IPOs since WWII.
But people aren't focused on the right things. That much new equity supply hitting in a few months creates a math problem: the money has to come from somewhere. Most of it will come from existing holdings. Passive funds will be forced buyers once these names join the indexes, which will happen much faster than usual, given recent index rule changes. That means mechanical selling pressure on whatever many funds currently own, which is mostly the same large-cap tech stocks everyone else owns.
The IPO Flow Impact Simulator lets you run the numbers. Set valuations, pick timing, adjust float. You can see where the pressure lands, and why the second half of 2026 will be the most unusual and risky in US equity supply history.
