Today is VIX settlement (quoted under the symbol VRO) day with June VIX Futures and Option contracts being cash settled with a value of 19.73. This is higher than the index closing of 18.26 and June future contract close of 18.20 from yesterday. The higher VIX settlement is a result of a spike in S&P 500 implied volatility that coincided with the big overnight drop in the level of the S&P 500 index.
This difference between the VRO and the VIX index will result in some value changes in the instruments that trade on the VIX. For instance the June VIX future contract closed with a value of $18,200, but will settle with a value of $19,730 – an increase of $1,530. Consider that a good thing for those that held their long position into settlement, but a negative surprise for those that held short positions over night.