Balancer, a prominent DeFi protocol, experienced a significant security breach in November 2025, resulting in losses exceeding $120 million. The attack targeted key assets, including ETH and derivatives, and highlighted vulnerabilities in smart contracts. Despite recovering $4.1 million, the incident raised serious concerns about DeFi security. The hack affected multiple networks, including Ethereum and Arbitrum, leading to a sharp decline in Balancer's total value locked (TVL) and governance token prices. Security experts have pointed out the risks associated with DeFi composability and access control, urging for enhanced audit practices and security measures to prevent future breaches.