Wall Street is assessing President Trump''s tariff salvo on Apple and what his giant tax bill means for the deficit and the economy.

U.S. stock index futures slid on Friday after President Donald Trump recommended 50% tariffs on the European Union, while Apple stock dropped after he warned that the company would have to pay tariffs if its phones were not made in the United States.

U.S. futures and global markets slumped Friday after President Donald Trump posted a pair of tariff threats on social media, one aimed at Apple and the other at the European Union. Futures for the S&P 500 and the Dow Jones Industrial Average slid 1.