The Fund invests primarily in equity securities of domestic and foreign companies that primarily own or operate assets used in the development, generation, production, transmission, storage and sale of alternative and renewable energy such as solar power, wind power, biofuels, hydropower, nuclear or geothermal power (collectively, Renewable Energy Infrastructure Companies). The Renewable Energy Infrastructure Companies in which the Fund may invest may range from small- to large-capitalization companies. The Fund also may invest in American Depository Receipts (ADRs) and Global Depository Receipts (GDRs) of Renewable Energy Infrastructure Companies. Under normal market conditions, the Fund will invest at least 80 percent of its net assets, plus borrowings for investment purposes, in Renewable Energy Infrastructure Companies.