This book provides the first systematic classification and treatment to essentially all exotic options currently trading at the Over-the-Counter (OTC) market. It contains exact closed-form pricing formulae and approximated closed-form pricing formulae for all popular exotic options. It includes arguments for and pricing formulae of exotic options with more flexibility than most popular exotic options such as flexible Asian options with flexible weights to various observations in the average, Asian barrier options, correlation digital options, etc. Most of the analyses in this book are within the Black-Scholes environment so that comparisons of each type of exotic options with the Black-Scholes model can be made readily. Emphases have been paid to illustrate the ideas of products clearly and show how to use the pricing expressions conveniently. The book contains many pricing formulae and analyses which do not exist in the literature.