Municipal Market Review 3Q 2026

Key Takeaways
Difficult Technicals Lead to Negative Quarter
Market Overview: How did munis perform in 3Q?
Municipal bonds (munis) sold off sharply during the third quarter of 2026, reversing the second quarter rally and marking its worst monthly performance since 2008. US Treasury yields also rose as the Federal Reserve (Fed) raised its policy rate by 25 basis points (bp) to 3.75 - 4.00% amid elevated inflation, the first hike since July 2023. Interest rate volatility persisted over the quarter, largely driven by geopolitical re-escalation in the Middle East and hawkish Fed policy expectations. Challenging muni technicals drove underperformance over the quarter; beyond the selloff in US Treasuries, slower seasonal reinvestment and heavy tax loss-related selling during a period of robust supply pushed muni yields to multi-decade highs.
Valuations: How did munis perform compared with US Treasuries in 3Q?
Muni yields rose 80 bp on average across the curve during September, compared with Treasury yields rising 50 bp on average. For the quarter, muni yields rose by an average of 120 bp, while Treasury yields rose 75 bp. Muni/Treasury ratios cheapened by 9% on average across the curve in September. For 3Q, ratios moved higher by an average of 13% across the curve, ending 3Q at 73%/78%/92% respectively for 5/10/30 years.

Source: Goldman Sachs Asset Management. Bloomberg. As of September 30, 2026.

Source: Goldman Sachs Asset Management. Bloomberg. As of September 30, 2026.
Index Performance: How did the investment grade and high yield portions of the market fare?
The Bloomberg Municipal Aggregate Index returned -4.36% in September and -6.35% for 3Q, marking its weakest 3Q performance since 1981. Meanwhile, the Bloomberg Muni High Yield Index also fell by -4.31% in September, and -5.55% for the quarter.

Source: Goldman Sachs Asset Management. Bloomberg. As of September 30, 2026.
Credit Research Spotlight: Tax Collections and Data Centers
State and Local Tax Collections: State and local tax collections continue to deliver strong results, with total tax revenues rising 6% for Q2 2026 compared with Q2 2025, according to the U.S. Census Bureau. This outpaces the 2.5% median state tax revenue growth projected by the National Association of State Budget Officers.
Data Centers and Munis: Data centers have emerged as a bipartisan election issue, with some jurisdictions imposing development moratoriums while others pursue expansion.
Read our latest insight on munis and data centers.
Muni Musings: Should investors capitalize on attractive yields in Q4?
We believe that fourth-quarter supply should remain high given continued infrastructure needs, but refinancing activity will be market dependent given the recent rate move. We expect demand to soften with year-end tax loss harvesting; however, attractive yields provide a compelling entry point.
In our view, Muni/US Treasury ratios are at fair value and credit spreads are below their five-year historical averages. With absolute yields at multi-decade highs, it presents a potentially attractive entry point for investors.
We anticipate headline-driven volatility to remain present, but we believe that healthy reserve balances and a resilient underlying economy continue to put municipalities in a strong position to navigate any headwinds.
Strong September supply
September new issue supply amounted to $55 billion ($52 billion tax-exempt and $3 billion taxable). This represented a 10% decline versus August but was 15% higher versus September 2025. Weekly new issuance volumes in September ranged from $10 billion to $16 billion.
For the third quarter, municipal issuance totaled $163 billion ($157 billion tax-exempt and $6 billion taxable). This was 2% lower than the previous quarter and 5% higher than the third quarter of 2025.

Source: Goldman Sachs Asset Management. The Bond Buyer, Barclays. As of September 30, 2026
Demand: Positive inflows
Munis saw volatile flows in September, experiencing the largest weekly outflow since April 2025 of $1.8 billion. September saw a rotation out of mutual funds into ETFs due to tax loss selling and inflows continued toward investment grade and long-term munis.
Muni fund flows totaled $5.2 billion for September. Year-to-date flows totaled $74 billion ($28 billion mutual funds and $46 billion ETFs), the second-fastest pace for the first half of a year. Investment grade quality munis saw strong flows at the intermediate and long-end of the curve.

Source: Goldman Sachs Asset Management. Refinitiv. As of September 30, 2026
Spreads: Tightening in 3Q
Spreads in BBB and high yield munis tightened 9 bp and 27 bp, respectively, in September, ending the month at 76 bp and 143 bp. For the third quarter, BBB and high yield spreads tightened 17 bp and 40 bp, respectively.
In the third quarter, transportation and education lagged most, returning -8.79% and 7.75% respectively, as all high yield cohorts posted negative returns that worsened with longer durations. In high yield for September, long maturities and transportation were the worst performers, falling 5.30% and 8.24% respectively.

Source: Goldman Sachs Asset Management, Bloomberg. As of September 30, 2026
