I've talked about US concentration (i.e. inflation) risk before... NASDAQ & SP500 are very much correlated due to Tech concentration (really Market Cap concentration in a few Tech names). With 25% in the SP500 & well over 50% in the NASDAQ, a $100 WTI will only exacerbate compression on US indexes, not help them. US markets are showing the cracks of too few of names with high market caps that are not inflation-hedged (look at the damage FB caused in the US indexes).
If playing the inflation card, one needs to focus on Commodity based markets (CAN, AU, etc). I fully expect US Markets to continue under performance in the near-mid term.