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 Stage Stores (NYSE: SSI) jumped 12% today on a spike in volume.

So what: Almost a million shares have traded hands so far today, nearly four times the three-month average. But there isn't any news out about the company or any press releases, so the reason for the move is a bit of a mystery.

Now what: When a stock moves this much with little or no news, I get alarm bells going off in my head. Maybe traders know something we don't, but there just isn't a solid reason to buy into this move today. I'm going to stick to the sidelines, as a speculative move just isn't something this Fool wants to be betting on.

Interested in more info on Stage Stores? Add it to your watchlist.

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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