The security issues of DeFi have always been a looming sword overhead. Imagine what would happen if those once-glorious top protocols suddenly face hacker attacks? Lending protocols, AMMs, derivatives contracts—each segmented track in history has experienced security incidents. From smart contract vulnerabilities to oracle attacks, from flash loan exploits to private key leaks, threats are constantly emerging. This is not alarmism, but a reality that must be faced in the ecosystem's development. Understanding the risks, choosing audited protocols, and managing assets properly are all fundamental skills for participating in DeFi.