The Dow closed lower by 817 points, or 1.91%. The broader S&P 500 slid 1.61% and the tech-heavy Nasdaq Composite fell 1.41%. The three major indexes each posted their worst day in one month. Stocks moved sharply lower and bonds sold off after a 1 p.

Apple sank after Trump threatened to put a 25% tariff on its products unless the company moves iPhone manufacturing to the U.S.