Paradoxically, the Japanese prime minister's confirmation on Monday that he would spend vast amounts of money on economic stimulus was positive both for the yen and the commodity-oriented currencies. The Canadian dollar strengthened by less than its antipodean peers, held back by news that the US economy grew by only 0.3%, less than half the expected amount, in the second quarter. It still managed to pick up four fifths of a US cent and went up by two and a half cents against sterling.

The pound's problem was Thursday's policy announcement by the Bank of England, which delivered much more than the expected quarter-percentage-point interest rate cut, from 0.5% to 0.25%. Not only did the Old Lady announce a fresh round of quantitative easing, the governor also made clear that Bank Rate could move even closer to zero before the end of the year. Sterling fell two cents in minutes.