In 2017, Griffin's work revealed that one or more market participants had been trading S&P 500 options in a way to artificially boost or depress the VIX, which would then have an impact on VIX futures. They argued that the volume of S&P 500 options would spike suspiciously at times, but only in the contracts that were used to help price the VIX. He claimed these trades simply didn't make sense unless somebody was trying to manipulate the VIX.