U.S. steelmaker stocks spiked on the expectation that they'll be able to charge more for their products, given that countries like China will have a tougher time flooding the U.S. market with subsidized steel.
But U.S. steelmaker customers, like domestic automakers, were particularly hard hit. And even foreign makers with major U.S. manufacturing facilities, which as Toyota, are warning of "substantially" higher prices.
Be smart: These immediate impacts were to be expected, including by the White House. But much more severe stock moves could come if foreign countries take retaliatory action against U.S. exporters — perhaps in sectors like agriculture — which is what classical economists predict will come next.