Wobbly week for US stocks; 2nd weekly drop for S&P 500

Stocks fell broadly on Wall Street Friday as investor jitters over the heated trade war between the world's two biggest economies overshadowed encouraging developments in conflicts between the U.S. and other key trading partners. The sell-off gained strength in the last hour of trading, handing the benchmark S&P 500 index its second straight weekly loss. News that the U.S. reached a deal with Canada and Mexico to scrap tariffs imposed by the Trump administration last year on imported steel and aluminum failed to cheer up investors.