that's all I am trading right now, USD. It's the one currency I am not afraid to be 100% long or 100% short. I fell asleep Fri am at 8:00 100% short USD, and woke up and still didn't make any money because I got stopped out too many times on the chop. I was flat AUD and went short at the very bottom, got stopped out and went long at the very top. (and this was all why I was asleep due to some stop loss and some stop to add open orders.)