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 Patriot Coal (NYSE: PCX) jumped 10% temporarily in intraday trading today on nearly double the normal daily volume.

So what: Shares of coal companies like Patriot, Arch Coal (NYSE: ACI), and Peabody Energy (NYSE: BTU) have been tumbling recently as coal prices have fallen. Today, shares are recovering from a plunge yesterday as traders see a technical bottom and value investors begin to move in, forcing volumes higher.

Now what: Coal is still a foundation of energy production in the U.S. and emerging markets like China. Shares of most coal producers have fallen sharply in recent months as concerns about the U.S. economy's growth, as well as Europe and Asia, weigh on investor's minds. The question is: How far can shares fall before they bottom?

Today looks a lot like a dead cat bounce after yesterday's drop, but I think there's starting to be some value in coal shares after the long fall.

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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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