This book revolves around the concept of financial risk tolerance and its role in financial markets. Bridging different literatures and reviewing in detail the impact of European regulation on the evolution of risk tolerance assessment, this book discusses the intersection of scholarly research, practitioner experience and current and likely normative developments. In particular, the book focuses on the evolution of the debate on the suitability questionnaire - a key tool introduced with the Markets in Financial Instruments Directive (MiFID) and further developed with MiFID's successor - comparing it with empirical evidence on financial risk tolerance determinants, spanning from sociodemographic to behavioral components and life events. The book also looks at the future evolution of the normative framework post MiFID2 addressing in detail two key trends that are already affecting the way in which risk tolerance is dealt with in European financial markets - sustainable development and fintech and roboadvisory. The book includes an original survey run with financial market experts to assess the perceptions regarding these two trends and includes commentaries by a professional financial advisor on the key topics discussed.