The astonishing rebound in stocks since early April largely reflects investors' bet that U.S. President Donald Trump won't follow through on his tariff threats.

President Trump is threatening Mexico and the European Union, two of the largest U.S. trading partners, with 30% tariffs starting in August if they don't reach a trade deal with the U.S. CBS News MoneyWatch correspondent Kelly O'Grady breaks down what this means for U.

President Donald Trump has posted two new letters on his social media platform announcing tariffs on the European Union and Mexico.

President Donald Trump posted letters to the leaders of Mexico and the European Union, saying they had not done enough to head off the new tariffs.

After European Union leaders said they would keep negotiating instead of immediately retaliating against President Trump’s latest threat, businesses remain unable to develop long-term plans.

It comes as US President Donald Trump threatens to impose 30% tariffs on imports from the European Union and Mexico.

"Imposing 30 percent tariffs on EU exports would disrupt essential transatlantic supply chains, to the detriment of businesses, consumers and patients on both sides of the Atlantic," European Commission President Ursula von der Leyen said in a statement on July 11, in a response to Trump's letter.

Latest news and live updates as Trump announces the U.S. will send Patriot missiles to Ukraine and meets with NATO's secretary general.