Wall Street falls as Brexit vote becomes major fear

The U.S. Federal Reserve began its two-day meeting to decide whether the U.S. economy has recovered enough to absorb an interest rate hike. Among banks that tend to benefit from higher interest rates, Wells Fargo and JPMorgan Chase took a hit and weighed most on the S&P 500. Adding to angst on Wall Street, recent opinion polls indicated growing support for Britain's exit from the European Union, creating a rush by investors to safe-haven assets like gold and the yen.