Panera Bread (NASDAQ:PNRA) has been on quite a tear lately, and today's same-store sales report is another case in point. Panera, known for its homemade bread and sandwiches, posted a nearly 10% increase in same-store sales. It's a far cry from last year, when such figures were more than a bit crumbly, but investors didn't seem too impressed today -- not that same-store sales should always be such a big deal, of course.

According to Panera's press announcement, for the four weeks ended June 14, the company's same-store sales increased 9.6%, which exceeded the company's 6.5% to 8% target for the entire second quarter. However, Panera stood pat when it comes to its second-quarter outlook, which remains in the $0.32-to-$0.33 per share range, an increase of about 50% over last year's figures.

Maybe investors have been spoiled by recent glowing earnings reports (if you'd like to refresh your memory, you'll find Foolish coverage here and here). In addition, year-over-year comparisons have been unusually kind to Panera, since 2004 was a carbohydrate-related company's nightmare. This time last year, many people eschewed bread to jump on the low-carb diet bandwagon; in the same period, same-store sales at Panera had slipped by nearly 1%, and flat or lower same-store sales were a huge trend for most of the year.

While there's nothing to complain about in Panera's projected second-quarter earnings, maybe investors feel that they've filled up on bread. This chart shows that over the course of the last year, the stock has trounced the S&P 500, having increased by nearly 75%.

Investors who got in while things looked downright dire last year have been rewarded handsomely. But now that all the positive sentiment has buoyed Panera's stock to 45 times earnings, investors might not consider it such a screaming bargain. It's probably wise for investors to wait and get to the meat of things when second-quarter earnings come out.

Will Panera continue to rise, or have its good times turned stale? Talk to Fools about Panera's future on our Panera discussion board.

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Alyce Lomax has no financial position in any of the companies mentioned.