State Borrowing at 10-Year High, But Muni ETFs Still Going Strong January 13, 2021 The municipal bond market is experiencing a boom as more states seek to capitalize on low rates to issue new debt to cover rising costs. Municipal bond exchange traded funds continue to strengthen as income hunters look for more attractive yield-generating assets in a lower-for-longer rate environment. Over the past three months, the SPDR Nuveen Bloomberg Barclays Municipal Bond ETF (NYSEArca: TFI) was up 1.9%. According to Refinitiv data, muni bonds for new projects hit $252 billion in 2020, after municipal bond issuance in 2020 was at its highest in a decade. The new borrowing put the total amount of outstanding municipal debt above $3.9 trillion for the first time since 2013, the Wall Street Journal reports.