[ by Howard Haykin ]

Since the equity markets have largely moved onto electronic systems that are meant to work without the traditional army of floor specialists barking out orders, Exchanges had hoped that computerized platforms would allow the markets to open today, Monday, without endangering even a smaller number of staff members.

Daylong discussions between the market operators and a group consisting of city and state officials, brokerages, the SEC, the Federal Reserve Bank of New York and Sifma, decided to be cautious and halt trading for the day. 

The NYSE issued this statement: "We support the consensus of the markets and the regulatory community that the dangerous conditions developing as a result of Hurricane Sandy will make it extremely difficult to ensure the safety of our people and communities, and safety must be our first priority."

Nasdaq made its final determination late Sunday evening (~ 10:30 pm).

Under the NYSE's contingency plan, traders would have routed their orders onto the company's electronic exchange, while electronic options trading would operate normally.  Volume was expected to be muted.

The decision on whether to close Tuesday will be made later. 

Even So, NYSE Was and Is Set to Trade.   A NYSE spokesman said the company's data center in Mahwah, NJ, which handles all trade orders, is intended to withstand a storm of Hurricane Sandy's strength. It also has generators and enough fuel to run for almost a week at current levels, with emergency plans in place to procure more fuel if needed, he added. 

Since 2007, the N.Y.S.E. has offered a "hybrid" model that allows trades to be completed either by humans or by computers through the Arca system. That gave the exchange a contingency plan that was previously unavailable, said Duncan L. Niederauer, the chief executive of NYSE Euronext. The company has tested the backup plan regularly, most recently in March.    [ Dealbook, 10/28/12 ].