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 NetSpend Holdings (Nasdaq: NTSP) initially surged more than 11% only to fall back to up 2% as of this writing. A rally in shares of peer Green Dot Corp. (Nasdaq: GDOT) may account for the gains.

So what: The rally is a rarity for both companies, which have suffered tough losses year to date. Shares of Green Dot have twice plunged more than 10% over the past month. Volatility, thy name is stocks in the prepaid banking industry.

Now what: For those willing to stomach the occasional bumps and bruises, there does appear to be a genuine -- perhaps even Rule Breaking -- opportunity here. NetSpend and Green Dot serve a base of some 60 million Americans who don’t have access to classic banking services.

Interested in more info on NetSpend Holdings and Green Dot Corp.? Add them to your watchlist. You can also try any of our Foolish newsletter services free for 30 days.

Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn’t own shares in any of the companies mentioned in this article at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Twitter as @milehighfool. You can also get his insights delivered directly to your RSS reader. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is also on Twitter as @TheMotleyFool. Its disclosure policy is at least 10% better than other disclosure policies.