Valero, Sunoco and Murphy Oil Corp. found bargains in the meltdown. In July 2007, VeraSun paid ASAlliances Biofuels LLC $725 million for three plants that can produce 330 million gallons a year, or $2.20 per gallon of distillation capacity. Valero, the U.S.'s largest independent refiner, bought two of them at 91 cents per gallon of capacity in December 2009, making the San Antonio, Texas, company the third-largest U.S. ethanol producer behind closely held Poet LLC in Sioux Falls, South Dakota, and Archer Daniels Midland Co.

Philadelphia-based Sunoco and Murphy in El Dorado, Arkansas, bought plants at similar discounts from Northeast Biofuels LP and AgStar Financial Services in Mankato, Minnesota. AgStar Financial was a VeraSun creditor. Fulton, New York-based Northeast Biofuels also filed for Chapter 11 protection. Green Plains also acquired two VeraSun refineries.

"Valero gets a big positive from what's going on in ethanol," said Paul Resnik, an analyst at Olympia Capital Markets Group in New York. "If you want to bet on ethanol prices rising, Archer Daniels Midland, Valero and Green Plains are it, and if I just wanted to have a rifle shot on ethanol I choose Green Plains."

Eoin Treacy's view Refiners have been the laggards of the energy sector. Most shares peaked in 2007, some even earlier. They remain in base formations when companies with greater access to upstream activities have done considerably better.

Valero continues to range mostly above $15 but with a downward bias. It needs to sustain a move above $22, breaking sequence of lower rally highs to indicate that demand is regaining the upper hand and to lend credence to a bullish hypothesis. Tesoro has a relatively similar pattern and needs to sustain a move above $16 to indicate a revival of bullish interest.

Sunoco is in a more well-defined base formation and needs to sustain a move above $35 to indicate a return to demand dominance.