I have found that NinjaTrader does not have intraday historical accuate data available. You can get daily data but no one has tick or minute data for any length much past a week. I think that is why they give you daily free, but tell you to get the other data from someone else. ( Nobody has it, and from what I have read if you do find it, you can't trust it).
I attended some of their online conferences, when I started asking how to get historical data and set my system to retrieve data, they would not answer my question, then they BLOCKED me from asking any question from that session and any future sessions.
I question whether the system will be worth much for back testing any intraday data!, of any size!.
When I do log back up to my broker for data the charts don't update, it seems that until they can figure out how to have updataed current data in the program, it is only good for live trading.
I don't know why they just don't fess up, they should make a disk up of accurate back data for their customers, and figure out a system to update the data in the program when you reconnect like other good programs do.
Have a Nice Day