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