For instance, more flexible bond ETF options include the PIMCO Total Return ETF (NYSEArca: BOND), an ETF version of PIMCO’s flagship Total Return Fund (PTTRX), which holds U.S. government debt 20.4%, mortgage 30.3%, investment-grade corporate debt 18.7%, high-yield bonds 6.2% and emerging market debt 15.4%.

Additionally, the SPDR DoubleLine Total Return Tactical ETF (NYSEArca: TOTL), an actively managed ETF that offers investors access to the investment process at Gundlach’s DoubleLine Capital, holds 54.4% mortgage-backed securities, 10.0% emerging market bonds, 9.4% bank loans, 7.1% commercial mortgage backed securities, 6.6% high-yield debt, 6.4% investment-grade corporate debt and 5.3% Treasuries.

The relatively new WisdomTree Western Asset Unconstrained Bond Fund (NasdaqGS: UBND) seeks high level of total return through both income and capital appreciation through an array of bond securities, including U.S. Treasuries, mortgage-backed securities, corporate bonds and foreign sovereign debt, among other bonds.  [A New Bond ETF With no Constraints]

The recently launched Newfleet Multi-Sector Unconstrained Bond ETF (NYSEArca: NFLT), which began trading on August 10, also tries to provide high current income and capital appreciation. [Newfleet Enters the Fray with Unconstrained Bond ETF]

For more information on the fixed-income market, visit our bond ETFs category.

Max Chen contributed to this article.