What: Shares of Dunkin' Brands Group (NASDAQ:DNKN) were down 11% as of 11 a.m. Thursday after the doughnut and coffee specialist issued disappointing forward guidance during its 2015 investor and analyst day.

So what: Specifically, management confirmed third-quarter U.S. same-store sales increased 1.1%, near the low end of its 2015 guidance for same-store sales growth of 1% to 3%.

In addition, Dunkin' Brands now expects 2015 revenue to increase 6% to 8%, which should translate to earnings per share of $1.87 to $1.91. Analysts, on average, were anticipating 2015 revenue growth at the high end of that range, with earnings of $1.92 per share.

Now what: Going forward, Dunkin' also reiterated guidance for development of 410 to 440 net new Dunkin' Donuts restaurants in the U.S. this year -- though this doesn't include impending plans to close 100 franchise-owned, Speedway-operated self-service locations. To Dunkin's credit, however, those locations represent a negligible amount of overall sales, and according to management could allow the company to re-enter the areas with full-menu traditional locations. At the same time, Dunkin' intends to follow Starbucks' lead by initiating tests for mobile ordering in Portland next month. If all goes well, Dunkin's mobile ordering platform will be rolled out nationwide by the end of next year. 

But while these actions might well help Dunkin' turn things around, that offers little solace for shareholders as it continues to trail the competition. Given Dunkin Brand's freshly reduced guidance, and with plenty of work to do before it wins back the affections of investors, I can't blame the market for bidding shares down today.

Editor's note: This article has been updated to clarify location closure plans.