





NO.PZ2016062402000046 问题如下 Assume you are using a GARmol to forecast volatility thyou use to calculate the one-y VAR. If volatility is mereverting, whcyou sabout the T-y VAR? A.It is less ththe T×\sqrt T\timesT×one-y VAR. B.It is equto T×\sqrt T\timesT×one-y VAR. C.It is greater ththe T×\sqrt T\timesT×one-y VAR. It coulgreater or less ththe T×\sqrt T\timesT×one-y V If the initivolatility were equto the long-run volatility, then the T-y Vcoulcomputeusing the square root of time rule, assuming normstributions. If the starting volatility were higher, then the T-y Vshoulless ththe T×\sqrt T\timesT× one-y VAR. Conversely, if the starting volatility were lower, then the T-y Vshoulmore ththe long-run value. However, the question es not incate the starting point. Hence, answer is correct. 老师讲课的时候,不是说出现mereverting的话,T日的标准差 直接用平方根法则计算的标准差么,原因是correlation 0。而如果是由tren话,则是T日的标准差 直接用平方根法则计算的标准差。原因是correlation 0。T日标准差会变得越来越大。具体到这道题,既然是mereverting的特点,那不就应该是T日的标准差 直接用平方根法则计算的标准差么?
NO.PZ2016062402000046 其中一个老师的解答中,提到目前的价格可能是高于也可能是低于均值的,所以计算的volatility也就变大或者变小,导致VAR变大或者变小。 那么那个天然气的题目中,是不是目前的价格也可以大于或者小于均值呢?这两种思路不矛盾么? 烦请老师解答。
NO.PZ2016062402000046 上一题明明是小于根号下T天的波动率,这题就变成即可大于也可小于了
NO.PZ2016062402000046 没有理解这道题的
不是说 均值复归则ρ<0,那么算出的σ是会小于均值复归的σ,VAR也是如此吗?