Just as investors thought they could take a break from tariff scares, President Trump’s threats of new levies against the EU and Apple threw trade tensions back into focus ahead of a long holiday weekend.

Stock futures rose Tuesday after President Donald Trump did a 180-degree turn on his threat to place a massive 50% tariff on goods imported from the European Union. Dow futures were up 600 points, or 1.

Markets are reacting sharply to unexpected political moves. Here's what's fueling the uncertainty — and why it could matter for your money.