The $38 million Rydex Utilities Investor Fund ( RYUIX) has edged up 8.9% this year and 20.5% over the past 12 months. Southern Co.. ( SO) is the fund's top holding, at 3.3%. It is up 5.9% this year. The company generates and distributes electricity to more than 4.4 million customers through its electric utilities in Alabama, Georgia, Florida and Mississippi. Power comes from company-owned plants. Dominion Resources ( D), at 3% of the fund, is up 14% this year. It is an integrated energy company that provides electricity to utility and merchant customers. It also owns gas and electric transmission lines and a liquid natural gas import terminal. The stock has a 4.1% dividend yield. Exelon ( EXC), at 3% of the fund, is up 2.2% this year. It's the parent of the utilities Commonwealth Edison of Illinois and PECO of Pennsylvania. It distributes electricity and natural gas to 5.4 million customers and owns 11 nuclear plants that generate 80% of its power.