Buoyed by optimism over its new Pretzel Bacon Cheeseburger, shares of Wendy's Co rose to their highest in more than five years.

Wendy's is keeping mum about its plans for a pretzel burger, but the item is already becoming the buzz of fast food.

Wendy's announces it is reuniting customers with the beloved pretzel bun to fill their hearts' desires with the return of both its Pretzel Bacon Chees