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 automotive parts retailer Advance Auto Parts (NYSE:AAP) soared 17% today after the company agreed to acquire General Parts International for $2.04 billion.

So what: Advance Auto is making the move to expand its geographic presence and, judging by the stock's big surge today, Mr. Market is thrilled with the price management is paying to do it. In fact, the deal would create North America's largest auto parts provider, with roughly $9.2 billion in sales, giving investors plenty of good vibes over its scale and competitive position going forward.

Now what: The deal is expected to close by late 2013 or early 2014. "We believe the combination of the two companies is a great fit and the synergy of GPII's assets with our capabilities will allow us to capitalize on market opportunities that will create value for our shareholders and provide even better service to our customers," Advance Auto CEO Darren Jackson said. With Advance Auto shares trading at a P/E of 20, however, that bullishness might now be baked into the valuation.

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.