Chipotle says a key sales figure turned positive last month, a possible sign that the burrito chain may be starting to recover from a food safety scare.
Shares of Chipotle rose to a high for the year.
The Denver company says sales at established stores jumped 14.7 percent in December. They fell 1.4 percent in November and fell 20.2 percent in October.
The rebound in the final month of the year eclipsed a disappointing outlook for the entire fourth quarter.
Chipotle expects sales at established restaurants to fall 4.8 percent in the final quarter of the year, which is a more significant deterioration than the 3.8 percent drop analysts expected, according to a survey by FactSet.