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 prepaid bank card issuer NetSpend Holdings (Nasdaq: NTSP) fell by as much as 14% in intraday trading after reporting worse-than-expected first-quarter results.

So what: Chalk it up the volatile nature of banking to the unbanked. Last month, both NetSpend and peer Green Dot (Nasdaq: GDOT) surged when optimists concluded that 60 million low-income Americans would turn to the prepaid market for relief.

Now what: But that vision is getting blurrier by the day. NetSpend's revenue rose 16% to $80.8 million, while adjusted profit increased a penny to $0.11 a share. Analysts were expecting $81 million and $0.12 a share, respectively.

Most of the per-share gains were lost to dilution as NetSpend's share count ballooned 8% from last year's Q1. Cash from operations declined over the same period. Both are bad signs -- more than enough to keep me away from this stock.

Interested in more info on NetSpend Holdings? Add it to your watchlist.