This book clearly elucidates extreme financial risks associated with rare events such as financial crashes. The highlight of the book is the delineation of various copulas in conjunction with financial dependences among different assets of a portfolio. In particular, the insightful discussion on quadrant and orthant dependences casts new light on the connection between marginal models and financial dependence. It is well organized and systematically brings a vivid portrayal of the subject to researchers and graduate students in mathematics and statistics..