The Dow Jones industrial average was down 180 points, or 1.2 per cent, to 16,136 in the first half-hour of trading Wednesday. It recovered some of an early loss that sent the index down as much as 369 points shortly after trading opened.
The Standard & Poor's 500 fell 19 points, or 1 per cent, to 1,858. The Nasdaq composite fell 45 points, also 1 per cent, to 4,181.
Banks and health care stocks fell the most in early trading.
Bond prices soared as investors shifted money into safe-haven investments. The yield on the 10-year Treasury note plunged to 1.92 per cent from 2.20 per cent the day before, a huge move.