小编导读：高顿网校免费题库，通过针对性地讲解、训练、答疑、模考，对学习过程进行全程跟踪、专家权威解析与指导，帮助考生全面提升备考效果。　　A portfolio manager is using an exponentially weighted moving average (EWMA) model to forecast volatility for a particular market parameter. What is the implication of an EWMA weighting parameter value of 0.84?
　　A. A greater weight is placed on the most recent change in parameter value than on the previous volatility estimate.
　　B. An equal weight is placed on the previous volatility estimate as on the most recent change in parameter value.
　　C. More information is required to determine the implication.
　　D. A greater weight is placed on the previous volatility estimate than on the most recent change in parameter value.
　　Answer：D
　　The EWMA weighting parameter of 0.84 indicates that a weighting of 0.84 will be placed on the previous volatility estimate and a weighting of 0.16 will be placed on the most recent change in the parameter value.