Nvidia stock was slumping Tuesday following a report about harsher curbs on chip sales to China ahead of a make-or-break quarterly earnings report. Shares of the semiconductor maker were down 2.7% to $126.

What happens with Nvidia matters for the entire U.S. stock market. The chip company has grown into the second-largest company on Wall Street, which means the stock’s movement carries more weight on the S&P 500 and other indexes than every company except Apple. The tech giant, based in Santa Clara, California, is now worth over $3 trillion.

Those issues have raised questions over Nvidia’s near-term financials. And those questions have arrived as investors reckon with the prospect of slower growth from the company and other Big Tech players that have gone all in on AI — generally by spending billions and loading up on Nvidia’s chips.