The asset has also helped buoy investor portfolios in times of distress. Over the past three decades, the Barclays Municipal Bond Index has only showed four negative calendar-year returns.

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A Federal Reserve rate hike is one of the biggest risks that fixed-income investors face today. The Fed, though, has been pushing off on an additional rate hike and stated that there will likely only be two hikes this year. Nevertheless, Deutsche believes that munis could hold up better than other categories in a rising rate environment.

“Given the current uncertainty around interest rates, fixed-income positions are at greater risk of losing value, tax-exempt municipal bonds could potentially lessen this impact,” Lisa Poniewaz, ETF Regional Vice President at Deutsche Asset Management, said.

Investors interested in tapping into the muni bond market can look to the Deutsche X-Trackers Municipal Infrastructure Revenue Bond Fund (NYSEArca: RVNU), an efficient way to invest in lower quality investment-grade and longer maturity municipals, Goodfield said.

RVNU is the only U.S.-listed ETF that tracks long-term, investment-grade U.S. tax-exempt munis with dedicated revenue streams. The underlying index is intended to track federal tax-exempt municipal bonds that have been issued with the intention of funding, state and local infrastructure projects such as water and sewer systems, public power systems, toll roads, bridges, tunnels, and many other public use projects. The index will attempt to only hold those bonds issued by state and local municipalities where the interest and principal repayments are generated from dedicated revenue sources.

RVNU includes about a 67% tilt toward A- and BBB-rated debt, along with a 76% position in 20+ year maturities. The longer duration and slightly lower quality mix helps RVNU come with a yield-to-worst of 2.60%, compared to the 2.11% yield-to-worst for the Barclays Municipal Bond Index.

Financial advisors who are interested in learning more about the municipal bond market can listen to the webcast here on demand.