Overlapping area represents the amount of risk that can be diversified away by holding ProShares Ultra Bloomberg Natu and VelocityShares 3x Lng Crude Oi in the same portfolio assuming nothing else is changed. The correlation between historical prices or returns on VelocityShares 3x Lng and ProShares Ultra 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 ProShares Ultra Bloomberg Natural Gas are associated (or correlated) with VelocityShares 3x. Values of the correlation coefficient range from -1 to +1, where. The correlation of zero (0) is possible when the price movement of VelocityShares 3x Lng has no effect on the direction of ProShares Ultra i.e. ProShares Ultra and VelocityShares 3x go up and down completely randomly.