The investment seeks investment results that generally correspond (before fees and expenses) to the price and yield of the RAFI Investment Grade Bond Index (the "underlying index"). The fund generally will invest at least 80% of its total assets in the component securities that comprise the underlying index. The underlying index is comprised of U.S. dollar-denominated bonds registered for sale in the United States whose issuers are public companies listed on a major U.S. stock exchange. It is non-diversified.