Quote from bone:
There is an inherent limitation using the CQG spread trader or the TT AutoSpreader (using X-Study) - both platforms use the execution side price servers for technical study data feeds, so historical data is lost when the exchange shuts the servers down for maintenance each day. In other words, if you want to integrate historical data into your models you will have problems with some packages like the CQG Spread Trader or the TT AutoSpreader.
I beg to disagree. Not sure about TT's product but CQG owns and maintains its own ticker plant. Thus all of the historical data is available 24/7 independent of exchange schedules or connectivity. Users can review historical data all the time as long as their CQG is online.