SpaceX, OpenAI, and Anthropic are preparing blockbuster IPOs that will trigger unprecedented Wall Street trading activity under new "fast entry" rules. Nasdaq implemented changes allowing these stocks to enter indices within 15 days of listing, forcing passive investors to buy billions in new shares while selling existing holdings.

Elon Musk's SpaceX filed for what's expected to be the largest IPO on record, targeting a $1.75tn valuation. JPMorgan estimates $95bn of existing tech stocks would need to be sold if 50% of SpaceX shares are floated. The limited "free float" of shares available to public investors creates high demand, while index inclusion rules will artificially boost SpaceX's weighting to three times its float value.

Market participants brace for frantic trading as ETFs and passive funds rush to buy limited shares. "The most discussed trades" include betting against smaller stocks that might be booted from indices to make room for these megacap companies. Despite concerns about buying at inflated prices, the market appears ready to absorb these IPOs, with one hedge fund manager stating they're "going all in for maximum size on all of them."