NYSE to trade electronically Monday, shut floor The NYSE shut down on March 27, 1985 for Hurricane Gloria. Since the Great Depression, the longest suspension in trading at the NYSE occurred after the attacks on the World Trade Center on Sept. 11, 2011, when the exchange closed for four days. Forecasters said the monster combination could bring close to a foot of rain, a potentially lethal storm surge and punishing winds extending hundreds of miles outward from the storm's center.