Mrs Watanabe is crude shorthand for Japan's $15,000bn pool of savings, the deepest in the world and worth more than the annual economic output of the US. These vast resources are somewhat apocryphally marshalled by Japanese women, who have traditionally held a firm grip on family finances.

In fact, Mrs Watanabe is very crude shorthand indeed: she is just as likely to be Mr Watanabe, the manager of a Japanese life assurance company portfolio, or Mr Smith, an American hedge fund manager, borrowing in yen to buy South African rand, US mortgage-backed securities or tea futures. Whoever, she is, she borrowed cheaply in yen, courtesy of Japan's rock-bottom interest rates – which have been stuck between zero and 0.5 per cent since 1999 – and put the money in higher-yielding assets abroad.

The important thing to know about Mrs Watanabe is that, temporarily at least, she has all but stopped flapping her wings. In the past days, as spectacular moves in global currencies reveal, the carry trade has been violently unwound. With last week's panic retreat from risk assets of almost every description came a dramatic rise in the yen, partially reversed in the past two days on rumours of a Japanese interest rate cut. Even so, the yen was yesterday trading at about Y97 to the dollar, the other “safe haven” currency, against a remarkably steady Y110-Y120 in recent years.