Oct 29, 2012
U.S. stock and options markets will be closed on Monday, and possibly Tuesday, as regulators, exchanges and brokers voiced concerns about the integrity of markets in the face of Hurricane Sandy.
Market participants and regulators decided to shut the market because the storm will make it difficult to ensure the safety of employees, major exchanges said.
The decision to close stock and options markets came after regulators, exchanges, and dealers discussed the unknowns that would have been tested if the markets opened on Monday, three of the sources said.
For example, NYSE Euronext’s  New York Stock Exchange had planned to shut its physical trading floor, which would have meant operating as an all-electronic exchange for the first time.