The investment seeks to track the investment results (before fees and expenses) of the FTSE RAFI TM Developed ex U.S. Mid-Small 1500 Index (the underlying index). The fund generally will invest at least 90% of its total assets in the securities that comprise the underlying index, as well as American depositary receipts (ADRs) and global depositary receipts (GDRs) that represent securities in the underlying index. The underlying index is comprised of securities of small-and mid-capitalization companies that are classified as developed within the country classification definition of FTSE, excluding the United States.