Chipotle Mexican Grill ( CMG) is enjoying a nice rebound in 2013. Shares of the popular fast-casual restaurant chain have rallied close to 12% this year after correcting hard last fall. In 2008, Chipotle was an anomaly, throwing off huge same-store growth rates at the exact same time that most other restaurant chains were struggling just to keep declines in the single-digits. But Chipotle's combination of bargain positioning and an emphasis on marketing its stance on quality ingredients proved to be the winning combination for consumers. By and large, it still is. Today, Chipotle boasts more than 1,200 restaurant locations spread across 42 states and four countries. Food costs remain an ongoing challenge for volume-movers like Chipotle because while values for many assets deflate, food commodity costs have been rising for the last several years. That said, Chipotle's skew towards higher-end, less commoditized ingredients should help diffuse its exposure relative to peers. One of the most impressive parts of CMG's growth story is how it's been financed. To date, Chipotle has almost exclusively used cash from operations to finance its growth so far, maintaining an immaterial amount of debt on its balance sheet that's more than offset by a $662 million cash and investment position. While shares are far from cheap right now, they don't justify the short interest ratio of 11.8 that's currently weighing them down.