US financial markets watch `zipper index'

The US financial markets are used to watching a host of indices. Market analysts spend long hours trying to anticipate trends in areas such as US consumer prices, housing starts, confidence indices and the like. But a new index has affected the dollar and the US markets this week. The "zipper index" has measured the, er, adventures of the US president and looks set to be a major impact on the market for some time to come.