Charge-time vs accrual-time yield fees in AMMs: a design choice most LPs never see
When a pool's creator raises the yield fee, does the new rate apply to yield that accrued before the change, or only to yield that accrues after? Balancer V3, Uniswap V4 hooks, and Curve pick different answers. The choice is invisible in the UI, matters to any LP holding liquid staking or restaking assets, and is defensible on both sides. This post walks the mechanics on-chain, quantifies the drift for a worked example, and offers a small checklist LPs can run before joining a creator-owned pool.