Nvidia’s (NVDA) stock is quickly rebounding from its steep post-earnings selloff and has recaptured its $3 trillion market capitalization.

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.