Nvidia Corp.’s $3 trillion run-up in market value in the two years since ChatGPT helped trigger an AI frenzy is bigger than any stock rally in history in such a short time span. But the landscape is now changing for the chipmaker.

That turbulence has been on display recently, with Nvidia shares slumping after a presentation by Chief Executive Officer Jensen Huang fell short of investors' high expectations

Drops for Nvidia and other superstar stocks are dragging U.S. indexes lower and keeping Wall Street stuck in its weekslong rut. The S&P 500 fell 0.8% early Monday. The index is coming off its fourth losing week in the last five.