Vertiv, Lumentum, Coherent, and EchoStar have seen gains following their inclusion in the S&P 500, while Match Group has been removed. Some outlets are highlighting the addition of certain stocks as a catalyst, possibly related to artificial intelligence. The changes to the S&P 500 may also have implications for index investors and potentially expose them to companies like SpaceX, although the exact effects on other stocks, such as SoFi, are unclear.