This chapter presents some closing thoughts on the key concepts discussed in the preceding chapters of this book. The book examines market efficiency and other models in an attempt to understand behaviour in practice. It considers the proposition that the market is inefficient in both the strong and semi-strong forms. The book explains that the manipulation of financial data may be common especially during those periods of the trade cycle when management and companies are under particular pressure to perform. It suggests that insider dealing probably occurs at least on a very minor level in virtually every merger bid and in respect of most other important announcements. The way forward according to the financial services authority (FSA) is a market abuse regime based on principle-based regulation focusing on compliance monitoring. Compliance monitoring is directed towards all types of financial crime in which market abuse is merely part.