Bolsa, mercados y cotizaciones
Wall Street flat as options expire
* Four types of June equity futures and options contracts expire Friday, a convergence known as quadruple witching.
* The Dow Jones industrial average edged up 4.53 points, or 0.04 percent, at 10,438.70. The Standard & Poor's 500 Index added 0.55 points, or 0.05 percent, to 1,116.59. The Nasdaq Composite Index put on 0.72 points, or 0.03 percent, to 2,307.88.
(Reporting by Leah Schnurr; editing by Jeffrey Benkoe)