There is huge open interest on the Aug 220 strike in SPY,
VVIX had an incredibly big up day, even if the SPX really didnt. The last time the VVIX moved like this...take a look:
Despite the sell off that ammounted to wiping out all of yesterday's gains and a VIX that wiped out most of yesterday's losses (weekend adjusted), one thing stood out to me...the total lack of demand for VIX options. Through out the day I saw very few serious call buyers of VIX, in addtion I really didnt seem many put buyers in SPX. Adjusted for price, VIX really didn't do much today, maybe that is part of the reason things were so anemic. Stock volume was shallow yesterday, option volume shallow today. In fact, about the only trading I saw was upside call buying.