Under normal market conditions, the Fund will invest in a combination of fixed-income securities, including, but not limited to high yield securities; obligations issued or guaranteed by the U.S. Government, its agencies or instrumentalities; mortgage-backed securities issued or guaranteed by the U.S. Government or its agencies or instrumentalities, including U.S. agency mortgage pass-through securities; commercial mortgage-backed securities (CMBS); non-agency residential mortgage-backed securities; mortgage to-be-announced (TBA) securities; municipal securities; securitized assets such as asset-backed securities; dollar-denominated and non-dollar-denominated debt obligations of U.S. or foreign issuers, including emerging market issuers; and money market securities. Depending on market conditions, the Fund may invest in other market sectors. The Fund may also gain exposure to fixed-income securities through its investments in affiliated investment companies, including other exchange-traded funds, that invest in such securities. The Fund may invest more than 10 percent of its total assets in such affiliated investment companies.