The firm reiterated an outperform rating with a $29 price target.
"The company has discovered powerful unlocks to unit growth, which appear underestimated by consensus and underappreciated by the stock's 23% valuation discount to peers," analyst Brian Bittner said.
Wendy's also has "solid operating fundamental despite turbulent industry dynamics."
Meanwhile the company's valuation discount compared to peers is due to its overlooked risk/reward profile, according to Oppenheimer.
Wendy's updated goal for 8,500 to 9,000 stores by 2025 has strong visibility, Monday's note says.
The fast food restaurant faces similar food/labor cost dynamics as its peers going into 2022, which led Oppenheimer to take a more conservative stance on the company's margins. The firm now expects margins of 16.8% next year, compared to its previous expectations of 17.9%.
Rival Restaurant Brands International QSR, which is the parent company of Burger King, Popeyes and Tim Hortons, has a valuation of 18x estimated EBITDA compared to Wendy's valuation of 13.8x.
That discounted valuation means Wendy's has room to run, according to Bittner.
"We believe buy-side estimates have adjusted slightly below sell-side as choppy industry-wide SSS and elevated commodity/labor expenses have been on full display all earnings season," Bittner said.
Shares of Wendy's Monday closed 0.9% higher at $22.93 a share.