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