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: Thursday was a good day for stocks -- unless the stock was named Clarcor (NYSE: CLC). As everyone else and his brother gained 2% in their portfolios today, Clarcor shareholders were forced to grin and bear a 3.5% loss.

So what: Ah, well. It could have been worse. At one point today, shares of this filter manufacturer were down 10%, hurt by an earnings release last night that, although not exactly bad (earnings were up 13%), nonetheless failed to meet Wall Street estimates.

Now what: Perversely, this may turn out to be good news for investors with a bit more patience than Clarcor's shareholders showed today. Consider: Management may have missed estimates in Q3, but it held firm on full-year guidance of $2.25 to $2.40 per share. So basically, management is telling us that whatever earnings the company failed to make in Q3, it expects to make up in Q4 -- the quarter we're in now.

And the bad news? Even if Clarcor manages to make its comeback and hit the tippet-top of its guidance, its shares will end the year costing 18.4 times earnings -- which to my Foolish eye, is too high for a 12% grower like Clarcor.

Want to find out more about Clarcor? Add it to your watchlist.