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

Stock markets were down in early trading on Friday after President Donald Trump said he wanted to impose a 50-percent tariff on the European Union and a new 25-percent tariff on iPhone maker Apple.The S&P 500 was down around 0.

President Trump's latest tariff threats dashed any hope of a sleepy Friday before the long weekend for Wall Street. The CBOE Volatility Index, or VIX, spiked from just above 20 to 24.70 after the president threatened 25% tariffs on iPhones made outside the U.

"There is a serious risk of a bond market crisis that could lead to a wider financial crisis," one economist said of the bill.

The Dow closed lower by 817 points, or 1.91%. The broader S&P 500 slid 1.61% and the tech-heavy Nasdaq Composite fell 1.41%. The three major indexes each posted their worst day in one month.

US President Donald Trump’s signature tax bill passed the 435-member House of Representatives on Thursday morning by one vote. The sprawling, multitrillion-dollar package proposed by Republicans, which would (among many other things) slash funding for safety net programs in favor of extending tax cuts,