If one is a successful futures trader trading say 5 contracts at IB with a typical stop of 5 ES points that represents 2% of his trading capital, that means he has roughly 70k, but only needs about 10k for margin requirements. Obviously you don't want to shave that margin requirement as thin as possible, but 70k seems like overkill (unless you really dig that great interest rate from IB). My question is, where do you park your under utilized trading capital? I'd like to shy away from stocks, since I'm fearful of undue influence on my day trading. . .