Chipotle Mexican Grill's earnings per share growth have been climbing higher at an appreciable rate. That sort of growth is nothing short of eye-catching, and the large investment held by insiders should certainly brighten the view of the company. The hope is, of course, that the strong growth marks a fundamental improvement in the business economics. So at the surface level, Chipotle Mexican Grill is worth putting on your watchlist; after all, shareholders do well when the market underestimates fast growing companies. You should always think about risks though. Case in point, we've spotted 1 warning sign for Chipotle Mexican Grill you should be aware of.