During July, the prices of oil exploration and coal stocks mentioned in my newsletter tumbled precipitously. For example, Arch Coal (NYSE: ACI) and Peabody Energy (NYSE: BTU) lost roughly a quarter of their value by the end of July and Ultra Petroleum (NYSE: UPL) and Southwestern Energy (NYSE: SWN) which had been up over 40% through June ended July up a relatively paltry 4% and 11% respectively.

I find this interesting because it violates one of the basic theories I have about what moves stock prices. This beat-and-raise theory says that if a company beats earnings estimates and raises its guidance, then the stock will rise. Otherwise it will fall. In the case of these four companies, each of them with the exception of Ultra which did not report, reported doubling or tripling of earnings and raised their guidance.

So why did their stocks fall? In the case of the oil and gas companies, it could be because of declining oil prices. Those peaked at $146 a barrel and recently traded at $127. But I am not aware of any diminution in the price of coal for which demand is strong due to Chinese and Indian infrastructure investment among other factors. Coal is used to make steel and to fire up power plants.