问题如下：
A company uses EWMA to estimate volatility day-by-day. What would be the general effect of changing the volatility parameter from 0.94 to (a) 0.84 and (b) 0.98?
选项：
解释：
(a) The day-to-day changes in the volatility estimates would be more variable; (b) the day-today changes in the volatility estimates would be less variable.
为什么会有这个结论，盼复
