Despite overall industry headwinds including weaker customer traffic and rising operating expenses, 2018 has seen a handful of restaurant stocks deliver great returns. Big winners have included Domino's Pizza, Fiesta Grill, and Chipotle Mexican Grill. That said, the overall trend for the industry has been negative, with the Dow Jones Restaurants & Bars Index dipping nearly 3%. With the year a little more than half over, it's a good time to take stock of some of the restaurant industry's biggest underperformers so far.