The investment seeks to replicate as closely as possible, before fees and expenses, the price and yield performance of the Market Vectors US Listed Biotech 25 Index. The fund normally invests at least 80% of its total assets in securities that comprise the fund's benchmark index. The Biotech Index is comprised of common stocks and depositary receipts of U.S. exchange-listed companies in the biotechnology industry. Such companies may include small- and medium-capitalization companies and foreign companies that are listed on a U.S. exchange. It is non-diversified.