MMIN vs MUB

MMINBNYLI MacKay Muni Insured ETF

MUBAiShares National Muni Bond ETF

In short

MMIN MacKay Shields has run this one since 2017 around a niche most muni ETFs ignore: insured municipal bonds, investment-grade paper carrying a bond insurer's policy. Actively managed, pays monthly, 0.30% net of a fee waiver.

MUB Municipal bonds, indexed and cheap. Since 2007, MUB has packaged investment-grade national munis into tax-exempt monthly income for five basis points a year, and it sits among the deepest pools in the muni-ETF aisle.

Stated mandate

MMIN The Fund seeks current income that is exempt from federal income tax.

MUB The fund seeks to track an index of investment-grade U.S. municipal bonds, providing diversified exposure to the national municipal-bond market and tax-exempt income.

Why people hold it

• MMIN The hook is the insurance: bonds whose timely principal and interest are covered by an insurer's policy, layered on the issuer's own investment-grade credit.sec.govsec.gov 2
• Actively run, not indexed. MacKay Shields sets a macro view on rates and tax policy, then picks individual bonds through bottom-up credit research.sec.gov
• Income is the mandate: current income exempt from federal income tax, paid out monthly across roughly 230 bonds.

• MUB 0.05% a year against a muni-ETF median near 0.30%. In a category built on modest, tax-exempt yields, that fee gap is real money left in the fund.
• The benchmark is AMT-free: the ICE AMT-Free US National Municipal Index screens out munis whose interest can be pulled into the alternative minimum tax.ishares.com
• Tracks its index closely, one of the tighter jobs in its peer group, and distributes monthly. A multi-billion-dollar fund that trades actively.
• Broad investment-grade exposure across the national muni market, spread over thousands of issuers rather than one state's budget.ishares.com

Worth knowing

• MMIN Active insured munis cost more than plain beta: 0.30% net of a fee waiver (0.46% gross), near the category median, versus VTEB at 0.03% and MUB at 0.05%.
• Insurance covers timely principal and interest, not market value, share price or distributions, and fund shares are not insured. Insurer downgrades can hit prices.sec.govsec.gov 2
• More than 25% of assets can sit in munis linked by one economic, business or political development. Trading is moderate rather than heavy, so spreads can matter.sec.gov

• MUB Two rivals undercut it: VTEB and SCMB both run 0.03%. A two-basis-point gap is small, but it is a gap.
• A bond fund with no maturity date to hold to. Share prices move with interest rates and muni credit conditions, both directions.
• National by design, so no single-state tilt and no in-state tax angle. iShares runs state-specific muni funds such as NYF for that job.

Full MMIN profile⁠

Full MUB profile⁠