It was a difficult week for investors, as the Standard & Poor's 500 stock index closed lower for the third straight week. The S&P 500 Index sank 1.3% on Friday. Closing at 2,752.06, the S&P 500 index was 6.5% from its all-time high on April 30th.

Friday's stock market drop came after President Donald J. Trump threatened late on Thursday that, unless the flow of South American migrants crossing into the U.S. through Mexico is reduced, the U.S. would impose a 5% tariff on imports from Mexico starting June 10th, which would raise the levy on goods coming from Mexico by 5% a month to 25%.

Meanwhile, the trade war with China showed no sign of being averted and the Chinese are making the dispute a point of national pride. The prospect of fighting a trade war on two fronts caused the market to slump on Friday.