FUMB vs SUB

FUMBCFirst Trust Ultra Short Duration Municipal ETF

SUBAiShares Short-Term National Muni Bond ETF

In short

FUMB Active ultra-short munis with a filter: First Trust's managers hand-pick bonds that fund basic infrastructure and essential local services, and keep portfolio duration under a year. Federally tax-exempt income, paid monthly, for 0.45%.

SUB Munis, but only the near end of the curve. Since 2008 SUB has tracked an AMT-free index of investment-grade municipal bonds maturing inside five years, paying tax-exempt income monthly with far less rate sensitivity than long-dated muni funds.

Stated mandate

FUMB FUMB seeks federally tax-exempt income while preserving capital. Normally, it invests at least 80% of net assets in municipal debt securities whose interest is exempt from regular federal income tax.

SUB The fund seeks to track an index of short-term, investment-grade U.S. municipal bonds maturing from one month through five years, providing tax-exempt income while managing interest-rate risk.

Why people hold it

• FUMB Built to sit at the very short end: the prospectus targets a weighted average duration of less than one year, the lever that governs how much a bond portfolio's price moves when rates move.sec.gov
• The selection screen is unusual for a park-your-cash fund: munis that meet basic infrastructure needs or critical community services, across at least 10 states, tilted toward growing populations and healthy employment.sec.gov
• Roughly 300 muni positions, with interest exempt from regular federal income tax, distributed monthly rather than quarterly.
• No index to copy. A human team picks the bonds and has run this mandate since the 2018 launch, which is early for an ultra-short muni ETF.sec.gov

• SUB Charges 0.07% a year against a category median near 0.30%. On tax-exempt bond income, that fee gap is a meaningful slice of what actually reaches you.
• Two dials set on purpose: maturities from one month to five years, and an AMT-free index, so neither rate swings nor the alternative minimum tax hit the same way.ishares.com
• A multi-billion-dollar fund running since 2008 under iShares, with tight tracking of its ICE benchmark. One of the sturdier implementations in the muni group.
• Pays monthly, so the tax-exempt income arrives on a regular cadence rather than in quarterly lumps.

Worth knowing

• FUMB 0.45% sits above the category median and well above index-run neighbors: VTES at 0.05%, SUB at 0.07%, GUMI at 0.16%. Active credit research is what the gap buys.
• Tax-exempt here means regular federal income tax. It is not automatically exempt from your state's income tax.
• A few-hundred-million-dollar fund that trades moderately, not one of the category's liquidity giants, so bid-ask spreads carry more weight on entry and exit.

• SUB The five-year ceiling is the whole design, and it cuts both ways: less rate sensitivity, but a shorter stretch of the curve to draw income from than full-maturity muni funds.
• This is a national portfolio. Single-state funds like NYF chase a home-state tax break that a nationwide muni basket cannot offer.
• Broad-maturity peers VTEB and SCMB run at 0.03%. The short-end tilt here costs a few basis points more.

Full FUMB profile⁠

Full SUB profile⁠