US stock markets tumble as investors shaken by Trump tariffs

US stock markets tumbled on Thursday as investors parsed the sweeping change in global trading following Donald Trump's announcement of a barrage of tariffs on the country's trading partners. All three major US index funds were down as trading started on Thursday morning. The tech-heavy Nasdaq fund was down 4.5%, while S&P 500 and the Dow dropped 3.4% and 2.7% at opening, respectively. Meanwhile, the US dollar hit a six-month low, going down at least 2.2% on Thursday morning compared to other major currencies. Though the US stock market has been used to tumultuous mornings over the last few weeks,…