It seems that Japanese retail traders have much less confidence in their home currency than they should have. The first thing most do when opening their highly leveraged FX trading accounts is to buy USD/JPY. This is at least what a few of my Japanese trading friends have done and in fact some of them are long with average positions above 100, yet they persevere. As Jamie mentioned earlier, new margin requirements to be introduced next week are having the effect of forcing retail traders to reduce their mainly short JPY positions.
With 1.5 million retail trading accounts in Japan, this can amount to quite a lot of selling in pairs like USD/JPY.
