USD over past few days, currently an anemic 71.X. Realize the dollar index was around 120 in 2001 before the Afghanistan invasion and Iraq sabre rattling...
Well, hindsight is always 20/20, but remember this is essentially gambling. You couldn't have known it'd go back to 915, and the real bugbear is that you have to make sure the difference is big enough to offset the costs of selling/buying.