The investment seeks to track the investment results of the S&P North American Natural Resources Sector Index composed of North American equities in the natural resources sector. The fund generally invests at least 80% of its assets in the component securities of its underlying index and may invest up to 20% of its assets in certain futures, options and swap contracts, cash and cash equivalents. The underlying index measures the performance of U.S.-traded stocks of natural resource-related companies in the U.S. and Canada.