Once again, it has paid handsomely to follow the investment genius of Japanese housewives. When currency markets gyrated to the hollering over carry trades at the end of February, Mrs Watanabe used the temporary jump in the yen to top up on foreign currency-denominated assets. Other investors followed and now the long-standing trends in carry-affected exchange rates are back in force. Since that wobble, the yen has risen 6 per cent versus the euro while the Australian dollar - a popular high-yielding currency - has surged.

This is because conditions have remained perfect for short-selling low-risk assets while buying risky ones: global growth is solid, inflation is moderate and volatility, in everything from equity markets to foreign exchange, has dropped again. It is not just hedge funds that have been reinvigorated: real money managers and individuals are also adding to carry trade momentum. For example, in the first week of April - the beginning of the new financial year in Japan - portfolio outflows exceeded inflows by Y761bn, 41 per cent above the previous week.