Markets on Wall Street and in Europe declined rapidly early Friday morning 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 1.5% and Nasdaq futures tumbled 1.7% before the bell. Oil prices fell and Treasury yields sank as well, AP reports.

Markets took a sharp turn downward after Trump posted on social media that he wants “a straight 50% Tariff” on the EU beginning June 1 because representatives of the bloc have been difficult in negotiations.

European markets fell nearly immediately after Trump's post on his own Truth Social site. Germany’s DAX quickly swung to a 1.9% loss, while the CAC 40 in Paris fell 2.4%. London's FTSE 100 shed 1.1%.

Global shares slip as investors register their worries about U.S. debt

Trump has dialled back or paused many of his tariff threats in recent weeks, bringing some peace to markets which had been swinging wildly in both directions for weeks as Trump fired off tariff threats.

Shares of Apple were down 3.8% in morning trading after Trump threatened to put a 25% tariff on Apple products unless the company moves its iPhone manufacturing to the United States.

The threat delivered over social media could dramatically increase the price of iPhones, potentially hurting sales and the profits of one of America’s leading technology companies.

US benchmark crude oil tumbled $1.07, or 1.3%, to $60.13 per barrel while Brent crude, the international standard, fell 99 cents to $63.45 per barrel.