This document introduces the Forecasting Extreme Events Risk (FEER) Index, which is described as a downside risk measure that is coherent, sensitive to high moments of a distribution, imposes a complete order on gambles based on stochastic dominance, and is dynamically calibrated to implied market probability. The FEER Index aims to forecast extreme events by serving as a measure of tail risk that incorporates information from options markets to assess rare but severe risks.