Piper Jaffray analyst Nicole Miller Regan remains cautious on shares of Fiesta Restaurant Group amid the rally on last night's Q1 results. Fiesta reported its first positive Pollo Tropical same-store sales result following strategic recovery efforts, Regan tells investors in a research note. She believes, however, that fundamentals of the business, alongside longer-term strategic value, support a nine times multiple. The analyst raised her price target for the shares to $19 from $15 and maintains an Underweight rating on the name. She sees "still sizable" negative traffic trends and a lack of consistent performance across geographies. Stephens this morning upgraded Fiesta Restaurant to Overweight.