A trader laughs as he works May 12 with colleagues on the floor of the New York Stock Exchange. A loss of momentum on Wall Street, dropping commodity prices and worries over Europe's debt problems caused world stock markets to sag Monday. (Associated Press)

Photo by: Richard Drew

A trader laughs as he works May 12 with colleagues on the floor of the New York Stock Exchange. A loss of momentum on Wall Street, dropping commodity prices and worries over Europe's debt problems caused world stock markets to sag Monday. (Associated Press)