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 apparel retailer Stein Mart, Inc. (NASDAQ:SMRT) plunged 10% today after its current-quarter outlook disappointed Wall Street.

So what: Stein Mart's third-quarter results -- breakeven EPS on a revenue increase of 6% -- were pretty much in line with estimates, but downbeat margin guidance for the fourth quarter is triggering concerns over slowing growth going forward. Of course, management cited more normal discount levels than last year and increased e-commerce sales -- which carry lower margins -- for the view, suggesting that its competitive position is at least holding up.

Now what: Management expects its gross profit rate for Q4 to decrease about 100 basis points year over year, resulting in a second-half rate lower than last year's second-half rate. "Our earnings continue to improve as a result of our continued sales momentum," CEO Jay Stein reassured investors. "We have been very focused on refining our brands, pricing and sales execution and the improvements are evident in our results." Of course, with Stein Mart shares still up more than 100% from its 52-week lows, I'd wait for an even bigger pullback before buying into that bullishness.