VIX index - In case you don't know, it is a non-normal distribution

The VIX move last week was large with current levels the highest since 2011; however, it should be remembered that the VIX does not behave according to a normal distribution. It has a very skewed distribution with the center of mass in the mid-teens level. This skew is more likely than what would be expected with a standard normal distribution. The data from Harbourfront Technologies provides a good look at the non-normality.

It is inappropriate to think of the large move last week as anything like a normal event. It was an extreme but cannot be placed in the context of a normal distribution.