From Schaeffer's Research:
With crude oil prices currently north of $100, and drivers across the world feeling pain at the pump, one would assume that oil refiners are having a banner year. The misconception that high oil prices drive profits higher for refiners is prevalent among many members of the general public. This is indeed false, as higher oil prices raise the input costs (crude that they purchase) without necessarily driving profit margins higher. There are many factors that can influence the profitability of refining companies, but perhaps the most important to consider are the crack spread, Brent Crude-West Texas Crude spread price, and seasonality.
Historically, refiners flourish between late February and mid-May, ahead of the busy driving season. For the most part, however, that hasn't been the case this year. Large-cap names such as Valero (VLO), Hess (HES), and Tesoro (TSO) have all substantially underperformed the broad market since late February. There are, however, two glaring exceptions to this generalization -- Western Refining (WNR) and Sunoco (SUN). For simplicity's sake, I'm excluding integrated oil names from this list, mainly because their increased refining costs are offset by their ability to produce their own raw crude oil...MORE
...From a sentiment perspective, analysts remain very bullishly aligned toward the refiners. Among HES, SUN, TSO, VLO, and WNR, there are currently a total of 22 "strong buy" ratings with only three ratings of "sell" or "strong sell." Additionally, short interest on these names is down by an average of 18% over the course of the past month. Now that sentiment is growing extremely rosy, and the fundamentals for these names have begun to break down, this could be an opportune time to take short positions in select refining names.