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 natural gas producer and explorer Williams Companies (NYSE: WMB) jumped as much as 13.7% in early action today on about 10 times the average trading volume.

So what: Williams reported earnings this morning, beating earnings expectations by $0.02 per share. But that wasn't the big news: Williams also announced a plan to split into two separate companies.

Now what: This was a long-expected move and a welcome one, as investors will get to pick whether they want to buy Williams' exploration business or the production side of things. Marathon Oil (NYSE: MRO) made a similar move in January and was immediately rewarded with a 10% share price jump of its own. Analysts expect El Paso (NYSE: EP) to follow these trendsetters, which explains El Paso's smaller jump today.

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