This chapter introduces the book and discusses the importance of managing operational risk in today's financial markets. It notes that globalization, technology advances, and industry consolidation have accelerated changes and increased competitive pressures. Effective risk management, including managing operational risk, is critical for financial institutions to deal with this challenging environment. The chapter traces the development of derivatives markets and risk management practices. It argues that as financial institutions become more integrated, decentralized, and technology-driven, managing operational and other non-market risks on an enterprise-wide basis is fundamental to their successful operations. Recent high-profile losses have highlighted the need to broaden risk management beyond just market and credit risks.