The fund normally invests at least 80% of investable assets in equity and equity-related securities of natural resource companies and in asset-based securities. Natural resource companies are U.S. and foreign (non-U.S. based) companies that own, explore, mine, process or otherwise develop, or provide goods and services with respect to, natural resources. Asset-based securities are securities, the values of which are related to the market value of a natural resource. The principal type of equity in which the fund invests is common stock.