1 Introduction In this introductory chapter, we first introduce the topic of this project and its relevance to research and practice. After the statement of the main objectives, we formulate its research questions and contributions. Following some important definitions, we c- clude this introduction by outlining the structure of this project report. 1. 1 Motivation For a long time, the predominant view in finance was that the variation of returns across stocks could be explained by their sensitivities (i. e., betas) to a single factor, the excess return of the market portfolio. This classical...