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 independent medical exam provider ExamWorks Group (NYSE: EXAM) gained as much as 12% in intraday trading today after the company announced a significant acquisition.

So what: As a roll-up of small IMEs, a lot of ExamWorks' strategy revolves around finding and executing acquisitions. After the close yesterday, the company announced that it will be buying MES Group, a Texas-based IME, peer review, and utilization review provider for the auto, disability, liability, and workers compensation markets. ExamWorks is paying $210 million for MES and will get a significant amount of heft. Over the past nine months, MES would have added roughly $100 million to ExamWorks' $170 million in revenue.

Now what: If we annualize the EBITDA contribution that ExamWorks expects to get from MES, the company appears to be paying roughly nine times EBITDA for the acquisition. On an absolute basis, that's not a radically cheap price, but it's not terribly pricey and it's a much lower valuation than what investors are currently awarding ExamWorks' shares. Management expects the acquisition will be accretive to both EBITDA and cash earnings.

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