A sensitivity analysis estimates the impact of a single risk factor or a small number of closely-related risk factors (e.g. interest rates, FX rates, real estate price, equity price etc.) on asset value, asset quality, earnings, capital or liquidity ratios. In most cases, sensitivity tests involve changing inputs or parameters without relating those changes to an underlying event or real-world outcome. While it is helpful to draw on extreme values from historical periods of stress, sensitivity tests should also include hypothetical extreme values to ensure that a wide range of possibilities are included.