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-REVERE Natural Gas Index(TM). The fund will normally invest at least 90% of its net assets plus the amount of any borrowings for investment purposes in common stocks that comprise the index. The index is an equal-weighted index comprised of exchange-listed companies that derive a substantial portion of their revenues from the exploration and production of natural gas. The fund is non-diversified.