One of, if not the, most important event of the week was the Federal Reserve's monetary policy decision on Wednesday and the subsequent press conference held by chairperson Janet Yellen. No change was expected to the benchmark Federal Funds rate but investors were eager to hear whether the Fed would adjust its previous guidance that interest rates could be increased four time this year. 

Indeed it had. Whilst Ms Yellen made no specific commitment, the written statement made it look as though only two increases were now on the cards and her comments did nothing to change that impression.

The softer tone led investors to mark down the dollar immediately by more than a cent and the erosion of its value continued on Thursday. Over the week the dollar lost two cents to sterling and it fell by a cent and a third against the euro, making it the weakest performer among the major currencies.