By TheStreet Staff What Is the Correlation Coefficient?The correlation coefficient is a metric that measures the strength and direction of a relationship between two securities or variables, such as a stock and a benchmark index, commodities, bonds, or other types of assets with data series. It can also be used to compare the performance of two different types of asset classes: a foreign currency and gold, the S&P 500 Index and a bond yield, an exchange-traded fund and crude oil, or even cryptocurrency and a benchmark tech stock index. This article focuses on stocks. Correlation measures the r…