Bolsa, mercados y cotizaciones
Wall Street ticks down at open, DuPont weighs
The Dow Jones industrial average fell 18.4 points, or 0.11 percent, to 16,827.73, the S&P 500 lost 2.97 points, or 0.15 percent, to 1,954.25 and the Nasdaq Composite dropped 3.73 points, or 0.09 percent, to 4,375.32.
(Reporting by Rodrigo Campos; Editing by Bernadette Baum)