Overlapping area represents the amount of risk that can be diversified away by holding NQPH and Bovespa in the same portfolio assuming nothing else is changed. The correlation between historical prices or returns on Bovespa and NQPH 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 NQPH are associated (or correlated) with Bovespa. Values of the correlation coefficient range from -1 to +1, where. The correlation of zero (0) is possible when the price movement of Bovespa has no effect on the direction of NQPH i.e. NQPH and Bovespa go up and down completely randomly.