It's been hip to be Square this year.
Shares of the mobile payment stock have surged 222 percent in 2017, including 13 percent last week alone following the announcement that it would begin testing bitcoin on its app and a big analyst upgrade. Evercore ISI upgraded Square to outperform on Friday and doubled its price target, citing Square's "new products with strong, omni-channel capabilities."
Despite the rally, Miller Tabak's Matt Maley believes the red hot tech stock will soon cool off.
"It's [trading] at a 90 percent premium to its 200-day moving average," Maley said Friday in a "Trading Nation" segment of CNBC's "Power Lunch." "You look at Facebook and during its first two years as a public company, it didn't get to a premium even half that big."
Square, led by Twitter CEO Jack Dorsey, celebrated its second anniversary of being public over the weekend with the stock up nearly 400 percent from its $9 IPO price.
"It's getting very stretched, and unless you think this is the next Facebook, this stock is going to have to pull back a bit before it goes any higher," Maley said. "And I question if it can go any higher from here at least in the near term."
Mark Tepper, CEO of Strategic Wealth Partners, also warns against Square's high valuation and what he perceives as weakness in their business model.
"Square has a good track record of losing money, and there's just no clear path to profitability in the near future," he said on "Power Lunch." "They've got good technology, but it's just not disruptive, and that's what you need in the industry."
In fact, Tepper finds the prospect of competition concerning for Square, given that its fees are high and its low profitability could put it in danger of other big names in the space like PayPal.
"When a competitor does enter their space, how will they be able to lower their fees so they can continue to compete?" Tepper asked. "We'd be staying away from Square at this point."
According to data from FactSet, 53 percent of Wall Street analysts covering Square have a buy rating on the stock, though the average price target is $38.56, well below Friday's levels.