The degree to which markets incorporate information is one of the most important questions facing economists today. This book provides a fascinating study of the existence and extent of information efficiency in financial markets, with a special focus on betting markets. Betting markets are selected for study because they incorporate features highly appropriate to a study of information efficiency, in particular the fact that each bet has a well-defined end point at which its value becomes certain. Using international examples, this is the first book to review and analyse the issue of information efficiency in both financial and betting markets. Part I is an extensive survey of the existing literature, while Part II presents a range of new readings by leading academics. Insights gained from the book will interest students of financial economics, financial market analysts, mathematicians and statisticians, and all those with a special interest in finance or gambling.