These are the biggest coffee chains in the U.S.

The coffee shop giant has spent the past 18 months returning to its roots as a coffee shop where customers want to stay. Now the company plans to go on offense.

Tennessee-based Bluemont Group was throwing away millions of dollars' worth of unsold doughnuts a year. Enter Do’Cast, an AI camera system that is helping it match supply with demand.

The Bottom Line: The two Mexican chains have long been among the industry’s most consistent performers. But that changed last year, at least for one of them.