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 Ralcorp Holdings (NYSE: RAH) jumped as much as 10% in midday trading on word ConAgra (NYSE: CAG) made an offer to buy the company.

So what: CNBC reported that ConAgra had made a bid about two months ago but talks are "no longer ongoing." As a result after initially spiking higher shares are now only trading about 7% higher.

Now what: Buying on buyout rumors is one thing but buying when you know a buyout isn't going to happen I am left scratching my head. Since we know ConAgra isn't in talks with Ralcorp now, and the bid was made months ago, I think the bounce we had today will soon die down. I'm definitely not jumping in on this move today and may look at it as an opportunity to sell for investors looking to get out.

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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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