Wall Street's major averages were significantly lower on Monday, as investors dealt with renewed uncertainty amid President Donald Trump's tariff news. President Donald Trump said via Truth Social that he issued letters to South Korea and Japan announcing 25% tariffs on imports beginning Aug.

U.S. stocks are lower on Monday after a three-day holiday break as investors keep an eye out for more trade-related developments.

The newest countries to be affected with Trump's Aug. 1 tariffs include Malaysia, Kazakhstan, South Africa, Laos and Myanmar. Trump shared letters that were sent to the nations, notifying them of levies ranging from 25% to 40%. They come on top of 25% tariffs imposed on Japan and South Korea.