What's Wrong With Chipotle Stock?

The fast casual chain is seeing declining sales volume.For years, Chipotle (CMG 1.55%) has been considered a bulletproof stock. After getting past its previous food health scares, the fast casual Mexican chain has steadily grown its unit count and per store sales, driving earnings higher and higher. Investors believed there was a huge runway for unit growth, both in the United States and internationally, and gave Chipotle stock a premium valuation because of it.Chinks may finally be showing up in Chipotle's ...