Buffalo Wild Wings (NASDAQ:BWLD) is a popular growth stock that many investors believe could go much higher in the years ahead. I disagree.

Many of my Foolish colleagues have written glowingly about Buffalo Wild Wings. In fact, there are many good arguments to buy the stock even as it approaches an all-time high. While I agree that the company has many things going for it, I believe its shares are flying too high and are due for a correction. Falling chicken wing prices and optimistic growth forecasts have elevated the stock to an unreasonable valuation.

Cheap wings, higher profits
One of the bullish factors leading to Buffalo Wild Wings' stock price increase -- the stock price has more than doubled over the last two years and it trades with a P/E of 32 --  is its outstanding profit growth. The company reported solid profit growth over the last two years partly due to falling wholesale wing prices. Chicken wings accounted for 25% of Buffalo Wild Wings' cost of sales in 2013, so fluctuations in the price can have a big impact on gross profitability. Buffalo Wild Wings' wholesale wing cost reached an all-time high in 2012, but declined 10.7% in 2013. Operating profit rose 22% last year partly due to a higher gross margin percentage as a result of falling wing prices.

However, wing prices have just skyrocketed again, threatening to lower the market's earnings expectations. Wing prices jumped to nearly $2 per pound in October, up from an average cost of $1.76 per pound in 2013. Management believes wholesale wing prices could remain elevated through the beginning of 2015. The company recently raised menu prices by 3% to help offset higher input prices, but its restaurants do not have enough pricing power to fully offset higher costs. As a result, rising wing prices could dampen Buffalo Wild Wings' profitability and cause investors to reevaluate the company's high earnings multiple.

Optimistic forecasts
While rising wing prices will serve as a short-term risk to Buffalo Wild Wings' stock price, the company's growth potential represents a longer-term risk. Management says there is a market for 1,700 locations in the U.S. and Canada, which offers a significant runway for growth from a current base of 1,051 locations.

However, there are a couple of reasons to doubt Buffalo Wild Wings' growth potential. First, the company is already among the largest casual dining chains in the United States. Applebee's (1,986 restaurants, including international locations) and Chili's (1,263 domestic locations) are the only comparable casual dining chains that have more U.S. locations than Buffalo Wild Wings -- both concepts have reached maturity and are shrinking. This should inspire little confidence that Buffalo Wild Wings' 1,700th location (or 1,600th, or 1,500th) will be a profitable use of cash.

The company's recent actions suggest that Buffalo Wild Wings' growth opportunities could soon become scarce. The company is investing in new concepts, like PizzaRev and Rusty Taco, in a sign that other investments hold more potential than adding new Buffalo Wild Wings locations. PizzaRev and Rusty Taco may turn out to be great concepts, but it should concern investors that management is turning its attention to other brands while claiming that Buffalo Wild Wings still has the potential to become the second-largest casual dining chain in the United States.