While the difference in price between domestic and foreign crudes may not be what it was a few months ago, the price difference between Canadian and US crudes is still great enough to make the premium for oil via rail to thrive today. Based on estimates, the amount of crude that will be moved by rail from Canada to the US will reach over 680,000 barrel per day within the next couple months. This is almost enough takeaway capacity as the Keystone XL Pipeline.

As investors, though, it's important to know who this impacts in a positive way. In the video below, Fool.com contributor Tyler Crowe explains why Canadian oil sands producers Suncor (SU -0.57%) and Canadian Natural Resources (CNQ -0.19%) will benefit more than others from the movement of oil sands out of Canada, and why mid-continent focused refiners like HollyFrontier (HFC) and CVR Refining (CVRR) are in the best position of the US refiners to capture value from these cheap rail shipments of Canadian crude.