Investors loved US President Donald Trump's 2017 tax cuts. But his trade policy has them tied up in knots.
In March, Mr Trump ordered tariffs on foreign steel and aluminium, as well as on billions of dollars worth in annual trade from China. He's threatened more, including on foreign cars.
The tariffs have already raised costs for US companies - and economists warn they threaten to slow growth, adding to recession worries.
Markets aren't sure about White House strategy, and an ongoing investigation of Mr Trump's election campaign ties to Russia has only added to uncertainty emanating from Washington.
"If these investigations produce some sort of smoking gun that throws us into a constitutional crisis, that might prove destabilising," says Mark Vitner, senior economist at Wells Fargo Securities.