The cost structure at big oil companies has grown dramatically, Jim Chanos says, with the cost...

The cost structure at big oil companies has grown dramatically, Jim Chanos says, with the cost of finding a marginal barrel "up and rising - a very, very negative trend." Singling out Exxon Mobil (XOM -0.8%), "it’s still not generating enough cash to cover all its cash needs," he says. "There’s a reason the stock has lagged despite its being the bluest of blue chips."