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 membrane maker Polypore International (NYSE: PPO) jumped 13% today after releasing fourth-quarter earnings.

So what: Sales rose 5% in the quarter to $169.4 million, and adjusted income from continuing operations was down 17% to $14.2 million, or $0.31 per share. When you add in that discontinued operations earnings were $0.39 per share, no matter what you compare it to, the company beat Wall Street's estimate of $0.40 per share in earnings.  

Now what: The bad news here is that Polypore's relationship with LG Chem has gotten so bad that it is taking legal action to protect intellectual property. That's a concern long term because litigation can be costly and doesn't guarantee a positive outcome. Given the slow growth and declining earnings, I'm not eager to jump into shares, but if Polypore can find growth in 2014, that opinion may change as the year goes on.