Chipotle Mexican Grill (NYSE:CMG) stock has been rolling like some of its burritos in recent months, and at least one Wall Street pro sees the shares heading even higher. John Staszak at Argus is upgrading shares of the fast-casual pioneer, lifting his rating on the stock from hold to buy.

Investors aren't going to look a gift upgrade in the queso-filled mouth, but the timing of the upgrade could've been better. Chipotle stock has soared 72% since bottoming out just three months ago ahead of Wednesday morning's analyst boost. The stock's been on fire since plucking Taco Bell chief Brian Niccol to step up as its new CEO, and one would think that the gains at this point will be harder to score given how Chipotle and the dining marketplace have changed since the days when Chipotle was a growth investor darling.

Interior of a Chipotle at Hollywood and Vine in California.

Image source: Chipotle Mexican Grill.

Taking another bite out of Chipotle 

Argus' Staszak feels that Chipotle's current valuation -- even with the shares rapidly outpacing its fundamentals in recent months -- doesn't adequately assess where the chain is in its turnaround. He sees comps and earnings growth accelerating in this multi-year recovery. He's also high on Niccol, expecting the new helmsman to enhance Chipotle's marketing strategy and food offerings to better stand out in this competitive climate. 

Staszak has an aggressive price target of $540. The previous high among his peers was a price goal of $530. He feels that Chipotle stock is cheap at roughly 41 times next year's earnings, though his argument that it's currently perched at the midpoint of its historical range of forward multiples between 16 and 76 over the past 10 years -- and deserves to be trading at the upper end of that range -- is a stretch. Chipotle isn't the cult fave it was in its 2015 prime.

The current turnaround is also no slam dunk to stick. Investors loved the better-than-expected financial performance, but last month's report had its pressure points. Comps rose 2.2% for the quarter, but the typical store saw its traffic continue to decline. Folks are spending more. There was a 4.9% uptick in the average check for the quarter, but how excited can you be about Chipotle when visits are going the wrong way?

Margins are improving, but we're also pitting financials against two years of depressed results. Earnings per share rose by a hearty 33%, but that per-share profit is 45% below what Chipotle earned during the first quarter of 2015. 

The last three months of gains have been fueled by the excitement of new leadership that we have yet to see in action and a somewhat lukewarm turnaround that we are seeing in action. It's OK to be optimistic and a Chipotle bull, but after the 72% pop and given the laundry list of mistakes that the chain has made, maybe the stock has risen to the point where it will need to prove that it earned its big three months of gains before amassing more upticks.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.