Record Muni ETF Inflows as Volatility Remains Low

U.S. municipal bond ETFs drew roughly $7 billion in net inflows in May, the largest monthly total on record, and about $24 billion year-to-date, according to Morningstar data cited in VanEck’s Muni Brief. The flow totals are through May 31, 2026.

Net flows covered a range of municipal exposures, including short-, intermediate- and long-duration funds and both investment-grade and high-yield segments.

Year-to-date realized volatility for broad investment-grade municipal bonds ran about 4–6% annualized through May 31, 2026. Short- to intermediate-term municipal debt showed realized volatility near 2% over the same period. Major equity benchmarks recorded higher realized volatility, about 13% for the Dow and more than 20% for the Nasdaq-100, the brief noted.

Morningstar data cited in the brief showed municipal Sharpe ratios remained supported by the combination of low volatility and generally strong underlying credit quality. The data indicates investors who maintained municipal exposure avoided the sharp equity drawdowns recorded in late March 2026.

On yield, ICE index figures referenced in the brief, with tax-equivalent yields calculated using a 37% federal tax rate, showed high-grade municipal bonds out-yielding Treasuries across much of the curve as of June 9, 2026. Both investment-grade and high-yield municipal bonds continued to offer comparatively attractive yields before tax adjustments.

The brief also listed standard risks for municipal securities: interest-rate risk, credit risk that is greater for lower-rated issuers, and call risk. Municipal income can be subject to state or local taxes and portions may be subject to the federal alternative minimum tax. High-yield municipal bonds carry a higher risk of loss of income and principal and tend to be more sensitive to local economic conditions and issuer-specific developments.

James Colby, senior municipal strategist at VanEck, wrote in the Muni Brief that continued investor caution about where to place new money could support further demand for municipal exposure. The note included the data sources and a reminder that past performance is not a guarantee of future results.