All three major indexes posted their worst weekly declines in months, ending a run of positive market moves. The S&P 500 fell 2.4%, marking its steepest drop since late May. The Dow slumped 2.9% in its worst week since early April,

Trump on Thursday signed an executive order that set new tariffs on a wide swath of U.S. trading partners to go into effect on Aug. 7. The order drew worries from Wall Street Friday as stocks slumped and Treasury yields fell sharply.