It's fair to say that Irene provided a good opportunity for Wall Street firms to work through sustainability and disaster preparedness issues. The long-wind-up to the main event gave the exchanges and banks time to ponder the issues and make sure they were fully backed up and prepared. Some sought to reassure the public and the trading community that with public statement attesting to their readiness.

So even with the storm bearing down on Manhattan, where more than a few residents were being evacuated, the top exchanges said they were not expecting anything other than a normal trading day on Monday. The multi-year rise of automated trading techniques means that it will be critical to have trading systems fully backed up in terms of emergency power.

Reuters reported that "inside its downtown Manhattan building, Big Board staff on Friday were prepping a backup power generator located well above the Wall Street-level trading floor. Extra fuel is in the basement and extra food is in the kitchen. Utility Consolidated Edison also said on Saturday it does not plan a widespread shutdown of New York City's power ahead of Hurricane Irene, although it may impose precautionary power cuts early on Sunday in low-lying areas of downtown Manhattan, where flooding threats are higher."

Meanwhile, banks were taking steps to make cash more widely available, including preparing "cash packs" and mobile ATMS. Branches are being kept open as well. A lot of ATMS  have been topped off.

For more:
- here's the article on exchanges
- here's an article on banks

Related articles:
Machine readable news still making gains   
Time to automate trade functions?