This book deliberately focuses on traditional methods of portfolio optimization and their most important extensions, as well as on the capital market theoretical standard models: Capital Asset Pricing Model (CAPM) and Arbitrage Pricing Theory (APT). After an introduction to the topic, the portfolio theoretical optimization approaches are presented before the capital market theoretical models, as the classical optimization approach by Markowitz is considered the foundation of equilibrium models in the capital market. The relevant moments of the return distribution, yield, and risk for both theories are described in detail, and their forecasting possibilities are examined.