Does the Capital Asset Pricing Model Work?

The capital asset pricing model (CAPM) is a theoretical representation of the way financial markets behave. It can be used to estimate a company's cost of equity capital in investment management decisions. Managers can also use CAPM to calculate divisional hurdle rates and risks of acquisitions. CAPM is based on specialized assumptions including frictionless markets without imperfections, such as transaction costs, taxes and restrictions on borrowing and short selling. It requires limiting assumptions concerning the statistical nature of securities' returns and investors' preferences, and it assumes investors' agreements on likely performance and risk of securities.