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)
This artist rendering shows the New York Stock Exchange's proposed trading-floor renovations, expected to be finished by the end of next year. The exchange plans on renting out its floor space for an increased number of events. (Associated Press)
Henry Becker directs trades in shares of MetLife on Thursday at the New York Stock Exchange, where investors watched stocks make substantial gains despite a surge in oil prices because of the turmoil in Libya and neighboring countries. (Associated Press)
NYSE Euronext CEO Duncan Niederauer listens as Manfred Gentz, right, Chairman of Deutsche Boerse, appears by video conference during a press conference at the New York Stock Exchange, Tuesday, Feb. 15, 2011. The NYSE and Deutsche Boerse announced Tuesday that they plan to merge. (AP Photo/Mark Lennihan)
Specialist Thomas Facchine (left) directs trades from his position on the floor of the New York Stock Exchange on Tuesday, when the Dow closed above 12,000 for the first time in 2½ years. (Associated Press)
A television monitor shows President Obama and Michele Obama as he presides over a national moment of silence, while specialists on the trading floor of the New York Stock Exchange observe the occasion for severely injured Arizona Rep. Gabrielle Giffords and the people who were killed during an assassination attempt against her, Monday, Jan. 10, 2011. (AP Photo/Richard Drew)
Traders Gregory Grassi (left) and Peter Tuchman confer on the floor of the New York Stock Exchange on Wednesday. The Dow Jones industrial average rose nearly 250 points, its biggest gain since Sept. 1.