Overlapping area represents the amount of risk that can be diversified away by holding UBS ETRACS CMCI Energy Total R and United States Oil in the same portfolio assuming nothing else is changed. The correlation between historical prices or returns on United States Oil and UBS ETRACS is a relative statistical measure of the degree to which these equity instruments tend to move together. The correlation coefficient measures the extent to which returns on UBS ETRACS CMCI Energy Total Return ETN are associated (or correlated) with United States. Values of the correlation coefficient range from -1 to +1, where. The correlation of zero (0) is possible when the price movement of United States Oil has no effect on the direction of UBS ETRACS i.e. UBS ETRACS and United States go up and down completely randomly.