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 lithium battery separator manufacturer Polypore International (UNKNOWN:PPO.DL) fell as much as 12% today, after releasing earnings.

So what: The company reported a 5.6% drop in revenue, to $180.2 million, which fell well below the $190.5 million analysts expected. On the bottom line, earnings per share of $0.43 were also below the $0.52 estimate from Wall Street, and no investor likes a double miss on earnings.  

Now what: Polypore's Celgard division, which supplies consumer electronics and electric vehicle markets, was the worst hit during the quarter. These were supposed to be big markets for the company, but electric vehicles, in particular, have been slowly adopted, leading to low demand. With sales down, and the stock trading at 22 times trailing earnings, I don't think now is the time to buy. Better to wait until operations turn around, and be late to the party than be early and get crushed in the process.

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