These are heavily influenced by supply and demand in a way equity derivatives are not. With equities, if the option (or future) were to be bid up past parity with the stock itself, this would present an arbitration opportunity which would quickly be taken up by someone who then takes up the other side on the derivative and the underlying for a guaranteed winning position (and thus bringing market forces into balance on the derivative). With something like the VIX, there is no underlying security to trade, so the markets can get quite far flung from the "intrinsic" value of the index. Add into that the VIX futures and options are based on expected value on expiration (not current spot value) and these are pretty far removed from the lock-step intrinsic / extrinsic valuation you see on equities. So I don't see anything particularly abnormal with these moving seemingly freely from their "underlying" and I'd expect today to show this particularly strongly. So yes, they should move predictably with the underlying, but they don't since there's no underlying to trade the arbitrage opportunity.