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