NEW YORK ( TheStreet) -- The energy stock buying and selling of the top hedge fund managers in the fourth quarter of 2011 showed heavy selling in oil service names, opportunistic buying in beaten-down value plays, and continued betting on the long-term future of natural gas even as prices remained at a historically low level. It's important to keep in mind, though, that while seeing what the big hedge fund managers have been buying and selling in any sector is interesting, it's backward-looking information. The activity often reflects short-term trades that may have already been closed out. When it comes to energy specifically, the fourth quarter was a trading environment for hedge fund managers that makes it even more difficult to determine if any long-term buying decisions within the energy stock universe were being made. The energy sector reached a one-year bottom just as September 2011 ended and the fourth quarter began. In other words, hedge fund managers were able to buy on the cheap in energy stocks and, if they wanted, turn these stocks for a quick profit as the sector rebounded. In October, the energy sector rose by close to 25% (see chart of the Energy Select Sector SPDR ( XLE) above). There are some trades quarter to quarter in energy stocks that should be discounted simply because the energy niches have always made for fast money opportunities. Take refining stocks like Valero Energy ( VLO) or Holly Frontier ( HFC). These refining stocks are among the most volatile trades day to day, and that is compounded by the fact that these stocks also hit 52-week lows during the fourth quarter. There are also plenty of M&A arbitrage plays among the hedge fund manager bets on energy, the most prominent being Kinder Morgan's ( KMI) acquisition of El Paso ( EP), which figured in many hedge fund portfolios' fourth-quarter action. Here, then, are four of the more interesting trends in energy stock trades revealed by the hedge fund managers' bets in the fourth quarter.