12. Conditional Unconditional â Average volatility is 15%â What is the current Volatility? Implicit Embedded in market prices Conditional A function of Yesterdayâs Variance (âconditionalâ on recent past)
16. EWMA Weighted Scheme Exponentially Weighted Moving Average (EWMA) Alphas are weights, so they must sum to one In EWMA weights also sum to one, however they decline in constant ratio (lambda)
17. EMWA (cont) Exponentially Weighted Moving Average (EWMA) RiskMetrics TM (EWMA) RiskMetrics TM is EWMA with a lambda (smoothing constant) of ~0.94 Lambda is the âpersistence parameterâ or âsmoothing constantâ