Separate warnings by the chipmaking giant and the chairman of the Federal Reserve about the impact of White House policies contributed to another sell-off on Wall Street.

U.S. stocks fell Wednesday after Nvidia warned new restrictions on exports to China will chisel billions of dollars off its results, while companies around the world said President Donald Trump’s trade war is clouding forecasts for how they and the economy will do this year.

The U.S. stock market experienced another day of turbulent trading on Monday. False reports about a potential tariff reprieve sent stocks gyrating. President Trump’s threat of additional tariffs on China later restored fears of a severe economic downturn.