That abrupt shift "from Tariff Man to global salesman," as investment strategist Ed Yardeni put it, revived an S&P 500 bull market in stocks.But just as the ride was smoothing out, markets got a jolt Friday morning as Trump threatened a 25% tariff on Apple iPhones if they're not manufactured in the U.

The president threatened both Apple and the European Union with higher tariffs on social media Friday morning, saying that trade talks with the Europeans had stalled.

President Donald Trump is threatening a 50% tax on all imports from the European Union as well a 25% tariff on Apple products unless iPhones are made in America.