Bolsa, mercados y cotizaciones
Wall Street opens flat ahead of Yellen
The Dow Jones industrial average fell 6.42 points or 0.04 percent, to 17,033.07, the S&P 500 lost 0.84 points or 0.04 percent, to 1,991.53 and the Nasdaq Composite added 2.32 points or 0.05 percent, to 4,534.43.
(Reporting by Ryan Vlastelica; Editing by Bernadette Baum)