Experts see the test - similar to Y2K-related initiatives in 1999 - as being an essential part of preparing the financial markets for an incident-free return to business.
Speaking to CNBC, Donald Marron, the chairman of UBS Warburg, said that to ensure the markets would run on 17 September, "We will need reliable power, communications, a [bank] clearing process and liquidity".
The clean-up process has not yet begun as rescue workers sift through the devastation in search of survivors, and questions also hang over the structural integrity of buildings surrounding the World Trade Centre. "We have to get our backup [IT systems working] without hampering the human element," said Marron.
"The markets must recommence in a complete fashion. We need to be sure all our systems work. That is why these trials over the weekend are so important."
He said that investment firms will need to test all their systems to make sure they can cope with the increased volume of trading which is expected.
While earlier reports described the targets of the US attack in New York, Washington and Pittsburgh as symbolic, experts are now talking of a real threat to the world economy. To maintain market liquidity, the US Federal Reserve is providing an extra $100bn (£68bn) of funding.
Preston Martin, the former Federal Reserve Board vice-chairman, said that by using sophisticated back-up and contingency, the banks that comprise the US Federal Reserve would remain operational in the event of a direct attack.
However, with all this preparation, there are still many physical obstacles standing in the way of the NYSE and other New York markets opening on 17 September. Most of the main routes into financial district are still blocked.