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 teen retailer Zumiez (Nasdaq: ZUMZ) climbed 12% today after its same-store sales and holiday-quarter guidance beat Wall Street expectations.

So what: Zumiez's December was so impressive -- stores open at least a year rose 10% versus the consensus of just 5% -- that analysts are being forced to increase their growth expectations yet again. Zumiez managed to top Wall Street's same-store sales estimates in all but two months during 2011, but with the stock once again approaching its 52-week highs, the bar will definitely be higher in 2012.

Now what: Expect the momentum to continue. The strong holiday season prompted management to up its fourth-quarter EPS forecast to $0.57 to $0.58, which also topped the average analyst estimate of $0.54. Of course, with the stock on a nice a run over the past few months and currently trading at a not-so-paltry P/E of 27, I'd wait until a little less optimism is baked into the shares.

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