This document discusses concepts related to measuring market risk and the Capital Asset Pricing Model (CAPM). It provides examples to illustrate how to calculate beta and the market risk premium. It also discusses limitations of CAPM and alternative models. The key points are:
1) Beta measures the sensitivity of a stock's returns to changes in the market and is used to estimate the expected return under CAPM.
2) CAPM holds that the expected return is equal to the risk-free rate plus the product of beta and the market risk premium.
3) Empirical tests have found mixed support for CAPM and alternative models like the Fama-French three-factor model may better explain returns.