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 natural gas shale producer Range Resources (NYSE: RRC) jumped as much as 10% today on unusually high volume.

So what: We were moving along in a normal trading pattern until, bam!, volume spiked and shares rose just after 11:00 ET. There are rumors swirling through the market that a non-U.S. suitor is pursuing the company, although they're just rumors right now.

Now what: Do traders know something we don't? Has news of a buyout offer leaked out of Range Resources? The answer for now is, we just don't know.

The trading pattern is very unusual today, but until I hear from management I wouldn't buy into market rumors. If you think Range Resources is a good buy, shares are now up just 5%, and a buyout would bring tremendous upside, but buy based on fundamentals, not rumors today.

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