U.S. stocks hit session lows on Friday as President Donald Trump appeared to mandate in a tweet that U.S. companies make their products at home and said he would hold a conference in the afternoon to discuss the matter. The Dow Jones Industrial Average DJIA, +1.33% fell 500 points, or 1.9% at 25,759, the S&P 500 index SPX, +1.59% fell 2% at 2,865, while the Nasdaq Composite Index COMP, +2.26% declined 2.3% lower at 7,806. Trump said "our great American companies" to "immediately start looking for an alternative to China, including bringing your companies HOME and making your products in the USA." The losses erased weekly gains for the S&P 500 and the Nasdaq while the Dow was off 0.1%. The Trump statement comes after the Chinese ministry indicated that it was preparing to raise tariffs in two batches on $75 billion in U.S. imports on Sept. 1 and Dec. 15, which would coincide with the dates that the U.S. is slated to increase tariffs on some $300 billion in China goods.