The investment seeks investment results that correspond generally to the price and yield (before the fund's fees and expenses) of an equity index called the ISE Clean Edge Water Index. The fund will normally invest at least 90% of its net assets (including investment borrowings) in the common stocks and depositary receipts that comprise the index. The index is designed to track the performance of small, mid and large capitalization companies that derive a substantial portion of their revenues from the potable water and wastewater industry, according to Clean Edge.