Commodity Volatility Indexes

One of the most exciting recent developments in volatility space was the launch of two commodity volatility indexes on CME - one based on NYMEX Crude Oil contract, and another on COMEX Gold. While there has been no volume in these products, I hope that will change when CME will list options before the end of the year. Meanwhile I started researching existing commodity volatility indexes. In the summer of 2008 CBOE launched two indexes: OVX based on USO options and GVZ based on GLD options, both using the same methodology as the VIX. In the October of this year, CME and CBOE announced creation of another two parallel indexes on crude oil and gold volatility, but based on CME contracts. Also Johannesburg Stock Exchange calculates SAVI White Maize - a 3 months volatility index for white maize, which (to a city person like myself) is some type of corn. Exchange summary is available here. At this point I believe these three are the only commodity products that have volatility indexes. If you know of any others, please send me an email. Since now there are many more indexes available for comparison, I decided to draw some charts. Below is the overlapping history of OVX index (based on USO) and OIV (based on CL) . As you can see that two indexes are comparable. What is interesting (and I have double-checked the data) is that it appears that OVX was leading OIV for about a year in the plot, until late 2009. In the past 12 months the apparent lead disappears, and indexes move more or less in tandem. Again, let me emphasize that I have not performed statistical tests to determine any lead / lag relationship; the statements above are based purely on eyeballing the charts. Oil volatility seems to be only slightly related to equity vol, which makes sense since the two are driven by different fundamentals. Gold volatility however, driven by dollar / inflation risks, does track VIX more closely.
I could not obtain historical data for GVX index from CME website, but would like to conduct a more thorough analysis of gold-equity volatility once data becomes available.
See more commodity volatility indexes here.