Long a Wall Street favorite, Nvidia has not outperformed the broader market recently, falling 3% over the last six months, worse than the S&P 500’s 7% return.

The report raised fears about the sustainability of AI infrastructure growth. That could mean less demand for Nvidia’s chips. TD Cowen’s Michael Elias said his team’s finding points to “a potential oversupply position” for Microsoft. Shares of Nvidia fell 4% on Friday.

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.