Palantir's price-to-sales ratio of 114 is way above OpenAI's 17. Palantir's success in defense work could block access to growth as enterprise AI payoff remains elusive

The sudden reversal shows how the hottest AI trade and top-performing stock of the year is colliding with a broader market rotation out of big tech.

Software stocks have been under pressure—and there may be more selling to come as highflying shares of Palantir finally succumb to gravity.

The heaviest weight on the market was Nvidia, whose chips are powering much of the move into AI. It sank 3.5%.

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 surged in the mania surrounding artificial-intelligence technology are dragging Wall Street lower again on Wednesday. The S&P 500 fell 0.9% and was on track for a fourth straight loss after setting an all-time high last week.