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What: Shares of fast food chain Jack in the Box (Nasdaq: JACK) tumbled 10% in intraday trading Tuesday after the company posted disappointing quarterly earnings. 

So what: Thanks to a $28 million charge related to 40 restaurant closings and increasing input costs, Jack in the Box's profit sank 90% in the fourth quarter. The company also posted a 3.3% decline in same-store sales, reflecting the frustrating headwinds that quick-service restaurants still face.

Now what: While business at Jack in the Box's namesake locations continue to slump, same-store sales at its Qdoba Mexican Grill managed to grow an impressive 5.6%. Management expects similar results from Qdoba next quarter, providing investors with a much-needed bright spot. Qdoba should only become a larger part of the business over time, so the stock's 10-ish P/E -- representing a clear discount to rivals McDonald's (NYSE: MCD), Yum Brands! (NYSE: YUM), and Chipotle Mexican Grill (NYSE: CMG) -- might be too tasty to pass up.

Interested in more info on Jack in the Box? Add it to your watchlist.

Fool contributor Brian Pacampara doesn't have a position in any of the companies mentioned. Chipotle is a Motley Fool Rule Breakers and a Motley Fool Hidden Gems selection. The Fool owns shares of Chipotle and Yum! Brands. Try any of our Foolish newsletter services free for 30 days.

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