The Short-Duration Fixed Income ETF will seek to achieve its investment objective through exposure to a broad portfolio of U.S. and foreign corporate debt securities with an investment grade rating. In addition, the Portfolio may invest in obligations issued or guaranteed by the U.S. and foreign governments, their agencies and instrumentalities, including mortgage-backed securities, bank obligations, commercial paper, repurchase agreements, money market funds, corporate debt obligations having investment grade ratings, securities of domestic or foreign issuers denominated in U.S. dollars but not trading in the United States, and obligations of supranational organizations. As a non-fundamental policy, under normal circumstances, at least 80% of the Portfolios net assets will be invested in fixed income securities considered to be investment grade quality. In addition, the Portfolio is authorized to invest more than 25% of its total assets in U.S. Treasury bonds, bills and notes, and obligations of federal agencies and instrumentalities. The Portfolio may invest in fixed income securities considered investment grade at the time of purchase (e.g., rated BBB- or above by S&P Global Ratings (S&P) or Fitch Ratings Ltd. (Fitch) or Baa3 or above by Moodys Investors Service, Inc. (Moodys)). The Portfolio may invest with an emphasis on debt securities rated in the lower half of the investment grade spectrum (e.g., rated BBB- to A+ by S&P or Fitch or Baa3 to A1 by Moodys). The Portfolio will not emphasize investments in the lower half of the investment grade spectrum, however, when the Advisor believes the expected credit premium (i.e., the expected incremental return on investment for holding obligations considered to have greater credit risk than direct obligations of the U.S. Treasury) is relatively low. At the present time, the Advisor expects that most investments will be made in the obligations of issuers that are located in developed countries. However, in the future, the Advisor may consider investing in issuers located in other countries as well.