Strategy. The Fund employs a passive management or indexing investment approach designed to track the performance of the Index. The Fund generally uses a representative sampling strategy to achieve its investment objective, meaning it generally will invest in a sample of the securities in the Index whose risk, return, and other characteristics resemble the risk, return, and other characteristics of the Index as a whole. Under normal circumstances, at least 80% of the Funds net assets, plus the amount of any borrowings for investment purposes, will be invested in the constituent securities of the Index and investments that have economic characteristics that are substantially similar to the economic characteristics of such constituent securities, which may include to-be-announced (TBA) transactions in mortgage-backed … Show more… The Fund employs a passive management or indexing investment approach designed to track the performance of the Index. The Fund generally uses a representative sampling strategy to achieve its investment objective, meaning it generally will invest in a sample of the securities in the Index whose risk, return, and other characteristics resemble the risk, return, and other characteristics of the Index as a whole. Under normal circumstances, at least 80% of the Funds net assets, plus the amount of any borrowings for investment purposes, will be invested in the constituent securities of the Index and investments that have economic characteristics that are substantially similar to the economic characteristics of such constituent securities, which may include to-be-announced (TBA) transactions in mortgage-backed securities, U.S. Treasury futures, and credit default swaps. Bloomberg Index Services Limited (the Index Provider), designed the Index to seek to provide comprehensive exposure to the U.S. dollar (USD)-denominated bond market, while enhancing yield within desired risk parameters and constraints, as described below. The Index is comprised of USD-denominated bonds. The Index deconstructs the USD-denominated bond market, as represented by USD-denominated, taxable bonds that are rated either investment grade ( i.e. , rated Baa3/BBB-/BBB- or above by Moodys, S&P Global Ratings (S&P), and Fitch, respectively) or high yield ( i.e. , rated Ba1/BB+/BB+ or below by Moodys, S&P, and Fitch, respectively), into one of the five categories of debt described below. The constituents in each category, except for US Investment Grade Debt, are weighted by market capitalization. The weighting of the constituents in the US Investment Grade Debt category is determined by the Index Providers proprietary weighting methodology, which is described below. US Investment Grade Debt This category is designed to broadly capture the USD-denominated investment grade bond market, which consists of Treasuries, government-related and corporate bonds, mortgage-backed securities, and asset-backed securities publicly issued in the U.S. or global markets. The weight of this category is determined by assigning 50% of a weight determined in accordance with the Index Providers proprietary, rules-based weighting methodology to those issuers assigned to the Bloomberg US Aggregate Bond Index and the other 50% of the weight to those issuers assigned to the Bloomberg US Aggregate Enhanced Yield Index. This proprietary weighting methodology is designed to earn a greater yield while generally seeking to maintain the risk characteristics of the market capitalization-weighted US Investment Grade Debt exposure. Restricted Securities This category consists of investment grade, USD-denominated privately-placed securities, including those sold in reliance on the U.S. Securities and Exchange Commissions (the SEC) Rule 144A and Regulation S, each of which is an exemption from the SEC registration requirements prescribed in Section 5 of the Securities Act of 1933 (the Securities Act) permitting, subject to certain conditions, the public resale of restricted securities. Eurodollar Debt Designed to broadly capture the USD-denominated investment grade Eurobond market, this category consists of investment grade debt denominated in U.S. dollars and publicly issued in non-U.S. developed/Eurobond markets. US Corporate High Yield Debt This category seeks to broadly capture the market of USD-denominated corporate bonds rated below investment grade, including debt issued by speculative issuers. US Emerging Markets Debt This category captures USD-denominated fixed-rate sovereign and corporate debt issued in emerging markets. To be eligible for inclusion in the Index, Treasuries, government-related bonds, and investment grade corporate bonds must have at least $300 million par amount outstanding. Mortgage-backed securities must have at least $1 billion par amount outstanding. Commercial mortgage-backed securities must have at least a $500 million minimum deal size with at least $300 million outstanding remaining in the deal and a $25 million minimum tranche size. Asset-backed securities must have at least a $500 million minimum deal size and a $25 million minimum tranche size. Restricted securities and Eurodollar issues must have at least $300 million par outstanding. High yield corporate bonds must have at least $150 million par amount outstanding. Emerging markets issues must have at least $500 million par outstanding at the security level, and the corporate issuers of emerging market bonds must have at least $1 billion in outstanding debt trading in the market. The Index is rebalanced on a monthly basis. To the extent the Index is concentrated in the securities of companies assigned to a particular industry or group of industries, the Fund will seek to concentrate its investments ( i.e. , invest more than 25% of its total assets) in such industry or group of industries to approximately the same extent as the Index. Show less