Forget the falling dollar. What we should fear is a rising yen. The most amazing statistic you never heard is: the year-to-date daily correlation between ups and downs in the global stock market versus spreads between the yen and the euro is 93 per cent. That is beyond eye-popping.

On days when the euro rises against the yen, stocks rise. On days when the yen rises to the euro, stocks fall. This year's daily yen/euro changes perfectly track this summer's stock market correction and subsequent resurrection. Make a chart of stocks, then the yen/euro spread; slip one on top of the other, and they are virtually indistinguishable.