Maybe this has been discussed in the past , but running a search for it is tough to sift through because the key words are quite abundant. Please don't tell me the VIX is the measure (unless I could be enlightened with some valid argument), because I don't think it is. On a day when the dow goes a hundred points down , a hundred points up, back down a hundred, and again up (there was a similar day to this description sometime in the last 2 weeks) , and the VIX ends the day DOWN, how is this a measure of volatility? So it's a fear vs. complacency factor... people are more fearful in downward markets, still not a lot of trading value in that common sense maxim, if you want to take some sort of advantage of the volatility. Point is, just looking at eod vix value will most certainly not help you see that, so what do you use then?