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) fell 11% today after General Motors (NYSE: GM) said it would shut down Chevy Volt production temporarily.

So what: The Volt isn't selling as well as GM had hoped and the company will shut down production for five weeks, starting in March. That could put a dent in Polypore's sales because the company is believed to supply materials for the Volt.

Now what: Since Volts weren't exactly charging off the shelf I don't think this derails Polypore's long-term financial future. It may be a small blip in coming quarters, but if you have your eye on this stock, I see today as a buying opportunity. Shares are trading at less than 14 times 2012 earnings estimates right now, a nice value for a company expected to grow earnings.

Interested in more info on Polypore International? Add it to your watchlist by clicking here.

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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