The Ultrashort Fixed Income ETF seeks to achieve its investment objective by generally investing in a universe of investment grade fixed income securities that typically mature in one year or less from the date of settlement. The Portfolio may, however, take a large position in securities maturing within two years from the date of settlement when higher yields are available. The Portfolio invests in U.S. government obligations, U.S. government agency obligations, dollar-denominated obligations of foreign issuers issued in the U.S., securities of domestic or foreign issuers denominated in U.S. dollars but not trading in the U.S., foreign government and agency obligations, bank obligations, including U.S. subsidiaries and branches of foreign banks, corporate obligations, commercial paper, repurchase agreements, money market funds and obligations of supranational organizations. As a non- fundamental policy, under normal circumstances, the Portfolio will invest at least 80% of its net assets in fixed income securities.