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 ZOLL Medical (Nasdaq: ZOLL) slumped more than 11% in early trading on heavy volume.

So what: No discernible news caused the downturn. Rather, it seems Big Money investors are choosing to dump their positions and shop elsewhere. More than 1.33 million shares changed hands -- a 264% increase from the average trading day.

Now what: Color me intrigued. Not only are the sales without context, but also the underlying business is showing positive inventory trends and trades for a noticeable discount to the long-term annual earnings growth rate analysts expect. Where do you stand on this stock? Would you buy at current levels? Please weigh in using the comments box below.

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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 Google+ or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

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