Now they have a trade war problem to worry about again. Stock futures fell sharply Friday after President Donald Trump brought the trade war back to the forefront with threats of massive tariffs against America’s most valuable company and one of its most important trading partners.

U.S. President Donald Trump's tariff decisions since he took office on January 20 have shocked financial markets and sent a wave of uncertainty through the global economy. Here is a timeline of the major developments: February 1 - Trump imposes 25% tariffs on Mexican and most Canadian imports and 10% on goods from China,

After frantically pushing share prices higher and lower for weeks on each twist and turn in Trump’s tariff negotiations, investors are starting to tune out the Trump trade war, focusing instead on rising bond yields and the US budget deficit.