The book offers an overview of the main financial and operational risks in cryptocurrency markets and Decentralized Finance. It outlines the role of stablecoins, crypto-investment products, and multi-function ecosystems, highlighting vulnerabilities linked to reserves, leverage, and protocol interdependencies. The book distinguishes traditional risks from those rooted in smart-contract logic, oracle manipulation, governance failures, and cross-chain bridges. An empirical section analyzes attack frequency, stolen amounts, and evolving exploit techniques, showing a shift toward complex schemes using flash loans and oracle distortions. The book also examines mixers and presents the Ronin case. The final chapters discuss technical and governance measures to mitigate risks and provide regulatory recommendations.