The document discusses capital asset pricing models, including the Capital Asset Pricing Model (CAPM) and the Arbitrage Pricing Theory (APT). It covers the assumptions and mechanics of the CAPM, how to estimate betas and expected returns, and limitations of the CAPM. It also introduces multifactor models like the Fama-French three factor model. The APT is presented as a more general alternative to the CAPM that does not require assuming a single market portfolio.