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: Bucyrus International (Nasdaq: BUCY) shares are up 28% today on news that the company would be acquired by Caterpillar (NYSE: CAT).

So what: The deal is worth about $7.6 billion, paying each Bucyrus shareholder $92 per share when completed. The move cements Caterpillar as the dominant leader in construction and mining equipment.

Now what: Shares in Bucyrus are trading at $89.71 as I am writing, so there is a little upside if investors want to hold on for an extra $2 and change. But many investors are focusing their attention on Caterpillar, who said it would pay for the acquisition through debt and a possible share offering. Caterpillar is up today, which makes me inclined to wait for a pullback until after the news dies down before jumping from the Bucyrus ship straight over to Caterpillar.

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