VIX futures market makers can hedge their volatility exposure by trading SPX options and futures. We use the daily VIX futures demand by VIX ETP issuers as an estimate of the end-of-day shock to market makers’ net position and find that the demand impacts the SPX futures market in the direction consistent with the VIX futures hedging channel. The VIX ETP demand is a strong predictor of the end-of-day SPX futures return in-sample and out-of-sample. We find evidence of a subsequent reversal, suggesting that VIX futures hedging activities can move the SPX futures market for reasons unrelated to price discovery.