Impermanent Loss
Also called: divergence loss, IL
Impermanent loss is the shortfall a liquidity provider suffers versus simply holding the two assets, caused by the pool automatically selling the rising asset and buying the falling one. It's only impermanent if prices return to where they started, which is why the name is misleading. A 4× price divergence produces roughly 20% loss against holding, which fee income may or may not cover.