As with any big system, spinning it up is much harder than bringing it down. After an outage, they have to stay offline to audit their systems to ensure that al

As with any big system, spinning it up is much harder than bringing it down. After an outage, they have to stay offline to audit their systems to ensure that all the nodes are synchronized, all queued trades have been processed, and no accounts are in invalid states. I'm sure they could have restarted in a matter of minutes, but the risk is ridiculously high.