Energy stocks have nothing to do with oil prices. They are toll operators, they make their money on QTY demanded. The reason oil stocks are volatile and trade at steep discounts to comparable companies is because of the volatility in their cash flows. They are as a group, very debt laden. And therefore HIGHLY sensitive to interest rates. If they can't roll their debt, they go under. These firms are very highly leveraged, always have been. The industry has always been like this. Not to mention many of these firms no matter how many times they swear at shareholder meetings that their trading operations are just for hedging, that's very far from the truth. They are HUGE speculators and therefore are vulnerable to huge trading losses. Honestly, the energy stocks are right on par with biotechs sans the trading aspect.
The irony is, most of these firms benefit more from lower oil prices, not higher. The reason being that higher prices bring high cost producers on the supply curve. That's more competition to sell less oil at the same price. Remember, QTY, not price, determines their revenues. So in general, the ones with the least debt, more integrated names, and most conservative in terms of trading, will trade at a premium to the rest of the group.
If you guys want to get some insight into this business, do a google search on the late Aubrey McClendon, who ran Chesapeake before he died. It was basically a hedge fund. The firm went from 5 million to 800 million back to almost bankrupt and then back to over a billion from the huge swings they had in nat gas trading. It's a fascinating company and he was a real interesting figure. Surely he was on the extremes but his legacy, just like the legacy of Enron, is all over the industry i.e. all the guys working there took that work ethos to other firms i.e Devon Energy.