Every three years, the Bank for International Settlements surveys the global currency market. Its latest report shows that the average daily turnover in the foreign exchange market reached a whopping US$4trn in April 2010, up 20% from April 2007. The most popular currencies remain the US dollar, euro and Japanese yen, which largely maintained their overall share of trading over the past three years.

Deeper digging into the results uncovers some interesting trends in certain currency pairs. Facing moribund growth at home, investors from the largest developed economies are looking to emerging markets for returns, fuelling rapid growth in, for example, the exchange of American dollars for Brazilian reais and Chinese yuan. Another particularly fast-growing pair, the yen-Australian dollar, reflects a growing appetite for commodities. By contrast, one of the only pairs to see trading volumes fall in recent years is the august “cable”, or trade between US dollars and British pounds.