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 Molycorp (NYSE: MCP) jumped 10% on speculation that rare-earth prices will rise due to Chinese action.

So what: China said it had just 23% of the world's rare-earth minerals, lower than the 36% the U.S. had estimated. Uncertainty about the level of rare-earth exports in the face of falling prices pushed the stock higher today.

Now what: There isn't any evidence yet that prices will go up due to any action out of China. In fact, prices have fallen dramatically over the past few quarters according to Lynas' published rare-earth prices. Increased supply has put a lot of pressure on prices and will continue to as Lynas and Molycorp increase production. I'm definitely not buying the jump today.

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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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