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 card company Green Dot (NYSE: GDOT) fell 10% today on unusually high volume.

So what: Volume is more than double the three-month average with two hours left in the trading day. The only news out from the company was a Securities and Exchange Commission filing yesterday that said one of its directors had chosen not to run for re-election.

Now what: Considering the lack of tangible news, I'm going to chalk up today's action to a crazy move in an otherwise calm market. I'm more inclined to be worried about falling estimates and regulatory changes than panic over today's move. For now, I'll stand firmly on the sidelines until I see a good reason to jump into this stock.

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