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 shoe seller DSW (NYSE: DSW) were tap dancing today as investors pushed them up as much as 18% in intraday trading on heavier-than-average volume.

So what: Before the market opened this morning, DSW announced better-than-expected first-quarter results. Sales were up 12% from last year to $504 million and were driven by a 10.8% jump in comparable store sales. After adjusting for acquisition costs, first-quarter earnings per share were $0.87, up handily from $0.67 in the first quarter of last year. Analysts were looking for $0.75 in earnings per share on $487 million in revenue.

Now what: The good news didn't end with the first-quarter numbers though. DSW also upped its guidance for its 2011 fiscal year, saying that sales will increase in the "mid single-digit range" and earnings per share will fall between $2.65 and $2.80. Analysts had been expecting $2.70 in per-share earnings for the year.

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