An introduction to the modern theory of asset pricing emphasizing discrete-time models . Its main focus is on the relationship between optimality and equilibrium . The first part of the course examines static and multiperiod economies in a discrete time and complete market environment. In this context the price of any security is simply its discounted expected payoff. In the second part we discuss the quantitative implications of equilibrium CCAPM and related topics (equity premium and bond premium puzzles).