U.S. oil refiners have delivered one of the stock market's biggest rallies of 2026, powered by soaring refining margins and geopolitical disruptions that have tightened global fuel supplies. But after gains that have dwarfed the broader market, history suggests the trade may be getting dangerously stretched.
Marathon Petroleum, Valero Energy and HF Sinclair have each surged more than 80% this year, compared with an approximately 11% gain for the S&P 500, according to a CNBC analysis. Marathon and Valero have nearly doubled, while Phillips 66 has climbed about 66%.