U.S. stocks are falling as investors worldwide pull away from the U.S. because of uncertainty caused by President Donald Trump’s trade war.

Trump’s headbutting with Fed Chairman Jerome Powell should be “taken very seriously and very negatively,” said one strategist, as Trump slammed the central banker as a “major loser.”

The S&P 500 sank 2.4% in another wipeout. That yanked the index that’s at the center of many 401(k) accounts 16% below its record set two months ago. The Dow Jones Industrial Average dropped 971 points,