According to @ambergroup_io, about $9M was drained from Yearn’s yETH through a Pi Collapse that exploited the StableSwap invariant without any code bug, indicating a design-level vector rather than a traditional hack. According to @ambergroup_io, this analysis highlights that DeFi positions tied to StableSwap-style liquidity pools face math-driven model risk that can affect LP capital, slippage, and liquidation dynamics, underscoring that DeFi security depends on mathematical invariants as much as smart contract code.