.IF THERE IS one iron rule of finance, it is actually that any program which seems to create significant, reliable revenues is actually concealing some correspondingly large risks. Past is actually packed along with instances of such money-spinners becoming wildly well-known, just for fans to belatedly realise that they can easily produce sudden reductions along with steady gains. Should that require bunches of individuals to desert comparable business simultaneously, the ripple effects can easily intimidate all sorts of other properties, or maybe the monetary unit itself. Think about the huge bets on subprime home loans that preceded the global economic crisis of 2007-09. The most recent example is the Oriental yen "carry exchange", the loosening up of which has been actually roiling markets due to the fact that mid-July while rapidly enhancing the market value of the yen. What is actually a lug exchange, and exactly how can it unwind thus violently?