I like Tom Mcclellans study from last year on the VIX OI data......since around 2017 significant market highs have formed with the OI north of 600,000 contracts. That process can take a while so it's not a timing tool, just a good indicator the flag is going up the pole. His theory was that the 600k level seems to be where the smart money starts to pile in and the OI reflects it pretty good. Peak open interest recently was as high as 549k in mid November, but the rest of the time at or below 450k. My price target on QQQ is around 240 based on the year long bottom formation in 2019. Still higher to go, consistent with the bullish sentiment period thru May. This runup is getting steeper with time on the NDX, so we should see it eventually in the VIX data.