Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of BJ's Restaurants (NASDAQ:BJRI) were getting thrown in the trash today, falling as much as 12% after serving up a lukewarm earnings report.

So what: Adjusted earnings per share were even with estimates at $0.27 a share, but GAAP EPS was down to $0.24 from $0.34 a year ago, though $0.06 in profit last year came from the extra week in the BJ's calendar year. Operating margin also decline by about 3 percentage points. Revenue increased 8% to $184.8 million, and same-store sales grew by 3%. BJ's opened five new restaurants, bringing its total count to 130, and plans to add 17 new restaurants in 2013.

Now what: Nothing was particularly bad about BJ's earnings report, considering it hit analyst views, but the drop in EPS and operating margin is disappointing for a stock trading at a P/E of 26 even after today's drop. The market was also probably hoping to see better results than the 8% top-line increase BJ's delivered. Still, this is primarily an expansion play, as BJ's is growing its store count by 13% this year and sees room in the market for as many as 425 restaurants nationwide. If the company can pull off that kind of growth, today's numbers will be just a blip on the radar.

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