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 Cobalt International Energy (NYSE: CIE) jumped as much as 22% today after the company extended a lease on an oil rig off the coast of Angola.

So what: The company said it had extended its lease with Diamond Offshore Drilling (NYSE: DO) for the rig Ocean Confidence by as much as two weeks. The rig is drilling for oil that lies at least 23,000 feet beneath the ocean's surface and is hoping to strike black gold on oil fields that contain an estimated 2 billion barrels of oil. Another explorer, Maersk Oil, reportedly hit the massive oil field and is waiting for government approval to release the results.

Now what: The news from Maersk Oil hasn't been confirmed yet, but judging by the market's reaction the numbers should be fantastic. Cobalt was unsuccessful in an initial well, and the hope is that the current wells being drilled will pay off big. I'm not buying on rumor, but if Cobalt can strike a rich well in the region, it could be a game changer.

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