They have a dozen tricks to get around that... e.g.

"The passive funds holding trillions of dollars of 401(k)s and other investments are rushing to change their rules as the IPOs of SpaceX, OpenAI and Anthropic draw closer."

Those index providers are the same interest class with VCs. With such moves they inflate demand post-IPO (hoping it holds for 180+ days), but also allows them to lure buyers in private secondary market and offload that shit pre-IPO.

https://www.wsj.com/finance/stocks/stock-indexes-are-contort...