Oanda makes clear that there is no insurance on any deposit and than in the case of the default, traders would fall under the category of general creditor.
8 figures under those circumstances? Give me a break!
And who accepted them on the other end? EU bankers (notably the Irish--enough said) who didn't do their homework. If a drug dealer offers you crack do you necessarily take it?
And you know this how? If you had looked at the actual numbers, you'd know that a few trillion is a drop in a bucket compared to what will be needed to start hyperinflation.