The book describes the application of economic theory to finance from the 1950s to the present, presenting the most popular models used to analyse financial instruments and markets, highlighting their application aspects and practical implications. The aim is not only to provide a discussion of the main topics for understanding market trends, prices and returns, but also to help the reader acquire conceptual tools, useful for composing portfolio structures by financial asset classes. A series of boxes illustrate possible applications, and exercises at the end of the chapters serve to explain some of the more technical elements.