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 insurer Phoenix Cos. (NYSE: PNX) surged more than 10% in intraday trading on no apparent news.

So what: "So what" is just about right. Often big stock movements can be explained by company news, events, or even something positive or negative happening with a competitor. Sometimes though -- as appears to be the case here -- momentum can just build up and push the stock in one direction or another without any clear driver.

Now what: Like fellow insurers CNO Financial (NYSE: CNO) and MetLife (NYSE: MET), Phoenix took its lumps from the recent financial crisis and the company reported losses in both 2008 and 2009. The poor performance slammed head-on into the stock, bringing it into penny stock territory. Investors interested in Phoenix will be best served by focusing in on the underlying company and the stock's valuation and ignoring movements like today's.

Interested in more info on Phoenix Companies? Add it to your watchlist here by clicking here.

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Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy assures you no Wookiees were harmed in the making of this article.