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 trucking equipment maker Wabash National (NYSE: WNC) are up 11% today after the company announced an acquisition.

So what: The company revealed that it would purchase Walker Group Holdings, a maker of liquid transport trailers, for $360 million. In fiscal 2011 Walker had revenue of $344 million and net income of $28.2 million.

Now what: The deal will immediately add to Wabash's earnings and improve the company's profit margins. Wells Fargo and Morgan Stanley have committed up to $450 million to fund the acquisition. This is a solid purchase for Wabash and should help earnings, but I'm not sure it warrants the pop we've seen in shares today, so I'm not buying the pop.

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