A three-week market sell-off intensified on Monday, with investors worried that tariff policy uncertainty would tip the economy into a recession, something President Donald Trump did not rule out over the weekend in an interview. The Dow Jones Industrial Average dropped 1,107 points, or 2.6% for its biggest decline of the year. The S&P 500 shed 3.4%, falling to the lowest level since September. The tech-heavy Nasdaq Composite saw the biggest selling of the major averages, falling 4.8% for its biggest decline since September 2022. The S&P 500 is off by 9.1% from its all-time high reached Feb. 19, the...