Nvidia, Palantir and other superstar AI stocks are dragging Wall Street lower again. The S&P 500 fell 0.5% Wednesday and was on track for a fourth straight loss after setting

The week’s biggest news for Wall Street is likely arriving on Friday, when Federal Reserve Chair Jerome Powell will give a highly anticipated speech in Jackson Hole, Wyoming. The setting has been home to big policy announcements from the Fed in the past, and the hope on Wall Street is that Powell will hint that an interest rate cut is coming soon.

U.S. stock indexes ended mixed on Wednesday after Nvidia, Palantir and other superstar stocks pared most of their steep losses from the morning. The S&P 500 dipped 0.2% after trimming a loss that reached 1.