With the double-levered long Vol ETF TVIX down 30% in the face of a falling equity market and rising VIX, reality appears to have been suspended. The crushing divide seems driven by the fact that Credit Suisse halted share creation forcing the ETF to behave more like a closed-end fund and with its massive premium to NAV (thanks to extreme hard-to-borrow-ness), this compression makes some 'technical' sense. While the Vol ETFs are designed to track VIX futures not spot, we remain skeptical of these instruments (or the options on them in their wonderfully compound manner) and although CS has said this cessation of share creation is temporary, it definitely brings up significant operational risks for anyone considering trading these vol plays.
The TVIX premium to NAV was huge at over 80% as it became hard-to-borrow and with today's action that premium is cut in half (and we assume NAV will rise given the pop in risk).
UPDATE: What is probably most likely the driver of the collapse, however, is the reversion to reality (akin to the NAV premium) as pointed out by Nic Colas (h/t) of TVIX (the actual equity position) to TVIXIV (the underlyting vol index itself)...