VIX is: Source: http://en.wikipedia.org/wiki/VIX I know there are VIX futures but not all brokers offer them so some people may have to trade ETFs instead. I've seen the following: VXX (S&P500 short-term futures) IVO (inverse) XXV (inverse S&P500) 2x: SVXY (ProShares short VIX short-term) TVIX (VelocityShares Daily 2x VIX short-term) VZZ (Long Enhanced S&P500 mid-term) VXZ (S&P500 VIX mid-term futures) VIXM (ProShares mid-term futures) VIXY (ProShares short-term futures) XVIX (daily long-short VIX) And more. Why are there so many? What is the difference between short, mid, and long term with regard to VIX indexes? I understand the difference between the regular and the 2x ones. Some of them are not what I expect. For example, here is a chart comparing VXX with XXV, which I would expect to be exact opposites of each other, yet they are obviously not: Why? Inverse S&P 500 ETFs are roughly the opposite of S&P 500 funds. Why is an inverse VIX ETF not roughly the opposite of a VIX ETF? Even two VIX ETFs that have the same description, such as TVIX and VIXY (both are 2x short term) are not even: Also, what happened to IVO?