The company's stock has climbed almost 30 percent over the past year.
The call comes nearly two months after the firm downgraded Wendy's to neutral over concerns the company would miss 4Q17 comp growth estimates. But, since then, the burger chain's 4Q same-store sales improved.
"Based on our latest checks for Wendy's to date in 1Q, we expect the company to beat comp estimates this quarter and potentially over the remainder of the year. Beyond 2018, we believe Wendy's contains one of the more impressive 3-5 year FCF growth stories within the publicly-traded restaurant sector."
Meanwhile, rival burger chain McDonald's shares have fallen more than 1 percent over the past week after Credit Suisse slashed its target a day after reiterating an outperform rating.
McDonald's also announced on Tuesday it will use fresh beef in some of its U.S. burgers. This news prompted Wendy's to fire back in a sassy series of tweets.
Wendy's has for years boasted its beef patties are never frozen, a distinction it says sets it apart from competitors.
"Some people are going to use fresh beef in SOME cheeseburgers, SOME of the time," Wendy's tweeted. "We believe in using fresh, never frozen beef in every cheeseburger everyday."
Wendy's rallied more than 4 percent following Longbow's report Thursday.