First Trust ISE-Revere Natural Gas Index Fund (the Fund) seeks investment results that correspond generally to the price and yield of the ISE-REVERE Natural Gas Index (the Index). The Index is an equal-weighted index consisting of exchange-listed companies that derive a substantial portion of their revenues from the exploration and production of natural gas. The Index is constructed by establishing the universe of stocks listed in the United States of companies involved in the natural gas exploration and production industries and then eliminates stocks whose natural gas proven reserves do not meet certain requirements. The Index then ranks all candidate stocks using four different methods, and often averaging the rankings, selects the top 30 stocks based on the final rank. The Index is rebalanced on a quarterly basis. The Fund will normally invest at least 90% of its total assets in common stocks that comprise the Index. Its investment advisor is First Trust Advisors L.P.