The CAPM provides a convenient measure of systematic risk. This measure, called beta(β), gauges the tendency of a security’s return to move in parallel with the overall market’s return (e.g., the return on the S&P 500). A stock with a beta of 1 tends to rise and fall the same percentage as the market (i.e., the S&P 500 index), Thus, β = 1 indicates an average level of systematic risk. Stocks with β > 1 tend to rise and fall by a greater percentage than the market. They have a high level of systematic risk and are very sensitive to market changes. Similarly, stocks with β < 1 have a low level of systematic risk and are less sensitive to market swings.