Thanks to cheaper oil in 2012, this U.S. refiner cashed in and made investors happy. Shares more than doubled amid a refining rally spurred by abundant oil in the U.S.
Western Refining owns refineries in Texas and New Mexico. In November, its stock rose to the highest in five years as oil produced in Midland, Texas, continued selling at a record discount to the U.S. benchmark. The refiner also gained from a boost in oil production in West Texas's Permian basin, which has helped push down crude prices in the region.
If prices remain low, investors may stay happy in 2013.
Wal-Mart retook the top spot, Berkshire Hathaway made the top five, and Apple grew enormously.