Assumptions

  • Investors can buy and sell all securities at competitive market prices (without incurring taxes or transactions costs) and can borrow and lend at the risk-free interest rate
  • Investors hold only efficient portfolios of traded securities - portfolios that yield the maximum expected return for a given level of volatility
  • Investors have homogeneous expectations regarding the volatilities, correlations, and expected returns of securities
    • Homogeneous Expectations … All investors have the same estimates concerning future investments and returns

Risk Premium

Security Market Line

  • plotting the expected return by the betas of each stock
  • insight: how risky is a stock compared to the market