Literature suggest strong relationships between energy markets and financial markets. While investors have a variety of methods they use for participating in the financial markets, one of the popular methods is through purchasing mutual fund shares. In addition to the increase in popularity of mutual funds, there has been a particular interest in funds that specialize in one or more sectors/industries. One of these types of funds that experienced a substantial increase in interest from investors is the energy sector mutual fund category. Academic research evaluating the relationship between sector funds and the rest of the markets is limited and research about energy mutual funds is even more scarce. In this chapter, we provide a brief summary of the previous and current research related to sector mutual funds while paying particular attention to the energy mutual fund space.