S&P Dow Jones Indices and Nasdaq are revising rules to allow faster inclusion of massive private companies like SpaceX and OpenAI. These firms could rank among the largest U.S. companies immediately upon listing due to their enormous market capitalizations.

S&P is considering cutting the required trading period for new listings from 12 months to six months. Nasdaq has already implemented a fast-track option for mega-cap stocks. Proposed adjustments also include waiving profitability requirements for the largest new listings.

These moves ensure benchmarks accurately reflect the market but force index funds to buy potentially volatile stocks. Trillions of dollars in passive investments would be required to purchase these high-valued shares shortly after their debut.