Nvidia, Palantir and other superstar AI stocks are dragging Wall Street lower again. The S&P 500 fell 0.9% Wednesday and was on track for a fourth straight loss after setting

U.S. stock indexes ended mixed after Nvidia, Palantir and other superstar stocks pared most of their steep losses from the morning

Nvidia, Palantir and other superstar stocks that had surged in the mania surrounding artificial-intelligence technology are dragging Wall Street lower again on Wednesday. The S&P 500 dropped 1% and was on track for its worst day since the first of the month.