Wall Street’s most exclusive club meets every quarter to decide who’s in and who’s out. It’s not a bank or a top-secret party — it’s the S&P 500. To join America’s biggest index, companies need to check a lot of boxes — four consecutive quarters of positive earnings, a market value of over $18B, and selection by a committee that curates the list. With the third quarter closing, two AI giants made the cut.

• On Sept. 23, PalantirPLTR
  and DellDELL
  will join the index following banner performances this year — with Palantir’s sales up 27% year-over-year and Dell’s AI server earnings jumping 80% in Q2.
• The two corporations will be among the S&P 500’s largest holdings, valued at $73B and $74B, respectively, after major stock gains.

Who’s out? Joining Palantir and Dell is insurance firm Erie IndemnityERIE

, while EtsyETSY

, Bio-Rad LaboratoriesBIO

, and American AirlinesAAL

get the boot after dropping 19%, 12%, and 21% over the past year. This shake-up shows just how coveted the large-cap index’s 500 spots are — and a reason why it has stood the test of time as America’s most-tracked funds. But with over a third of companies replaced within nine years, there’s always a chance for a comeback.