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 coal miner Alpha Natural Resources (NYSE: ANR) jumped 13% today after the company released a stellar earnings report.

So what: Revenue jumped to $2.3 billion, driven by the company's merger with Massey Energy. But the bottom line was truly impressive: Alpha reported adjusted earnings per share of $0.35, crushing the $0.04 analysts had expected.

Now what: Alpha's shares have been on a roller coaster, falling 11% earlier this week as talks in Europe fell apart. But this earnings report showed strong demand, especially out of China, and should ease the fears investors have had recently. I think this is very bullish for coal producers and Alpha in particular as demand continues to grow in emerging markets like China and India.

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