Currency as hedge for inevitable crash

There has been multiple euphoric episodes in equities that inevitably have led from boom to bust cycles, and when the downdraft comes, it is often difficult to find willing buyers for equities to get out. Dr Klaus Wellerschoff, Chief Economist of UBS Wealth Management recently went on an Asian tour and pointed out this interesting chart EUR/JPY cross currency rate versus Purchasing Power Parity of the Euro v Yen. There is a tendency of FX rates to revert to the mean of the PPP and overshoot to the other side after an extension. When and if world equities fall or correct, shorting the EURJPY will provide a 'hedge' for investors, is the argument.