Someone with a lot of money to spend has taken a bearish stance on Chipotle Mexican Grill CMG.And retail traders should know.We noticed this today when the big position showed up on publicly available options history that we track here at Benzinga.Whether this is an institution or just a wealthy individual, we don’t know. But when something this big happens with CMG, it often means somebody knows something is about to happen.So how do we know what this whale just did? Today, Benzinga’s options scanner spotted 46 uncommon options trades for Chipotle Mexican Grill.