The dollar had a bumpy ride this week, buffeted by comments from central banks in the US and Europe and finally stung by data on Friday showing US unemployment had risen at its fastest rate for 22 years.

Ben Bernanke, chairman of the Federal Reserve, inspired forex traders to buy the beleaguered currency on Tuesday when he said he was “attentive to” the impact of a weak dollar on inflation. The greenback immediately jumped 2.5 per cent against a basket of currencies and also made sharp gains against the euro.