TAXS vs ZMUN

TAXSANorthern Trust Short-Term Tax-Exempt Bond ETF

ZMUNCF/m Ultrashort Tax-Free Municipal ETF

In short

TAXS Northern Trust's muni index fund keeps every bond under five years to maturity and charges 0.05%, a fraction of the typical muni ETF fee. Roughly 1,700 federally tax-exempt bonds, none of them AMT bonds, with interest paid monthly.

ZMUN The first ETF built purely on callable munis, tracking an index F/m co-developed with Bloomberg. It buys investment-grade tax-exempt bonds already callable or callable within three months, which keeps the maturity clock very short.

Stated mandate

TAXS The fund seeks to track, before fees and expenses, the price and yield performance of the ICE Short-term Focused Municipal Bond Index. It is designed for tax-exempt income through passively managed, investment-grade municipal bonds with short-term maturities.

ZMUN The fund seeks to track, before fees and expenses, the price and yield performance of the Bloomberg Municipal Bond Currently Callable Index. It uses a passive representative-sampling approach focused on U.S. tax-exempt investment-grade municipal bonds that are currently callable or callable within three months.

Why people hold it

• TAXS 0.05% a year sits at the low end of the muni aisle, where the typical fund charges several times that, and matches the fee on MUB, the category's iShares heavyweight.
• Index rules admit only investment-grade bonds with under five years left to final maturity, so the portfolio skips the long-end price swings that define all-maturity muni funds.flexshares.com
• About 1,700 bonds, all exempt from federal tax and screened to exclude alternative minimum tax paper, with income distributed monthly rather than accrued.flexshares.com
• Passive, sampled, and run by Northern Trust's municipal desk, which has managed muni portfolios for more than 30 years. The index does the picking, not a manager's hunch.flexshares.comnortherntrust.com

• ZMUN A corner of the muni market nobody else had packaged: F/m calls it the first ETF dedicated to callable municipal bonds, on an index built with Bloomberg.fminvest.com
• The mechanism is the point: bonds callable now or within three months act like ultrashort paper, so price moves from rate swings tend to be muted.
• Interest is exempt from federal tax and, for some holders, certain state taxes. Spread across roughly 170 investment-grade issues, with cash paid monthly.
• No style drift: it is a passive representative-sampling fund, and the portfolio it holds matches the mandate written in its prospectus.

Worth knowing

• TAXS It launched in 2025 and trades lightly next to muni mainstays like VTEB and MUB, so spreads can run wider and the track record is short.
• Federally tax-exempt is not tax-free. That interest can still be taxed by your state and city.flexshares.com
• Sub-five-year munis generally carry lower yields than longer maturity portfolios. That is the other side of the milder rate sensitivity.flexshares.com

• ZMUN 0.30% a year sits above the short-muni group's 0.25% median, and far above the index giants VTES (0.05%) and SUB (0.07%).
• Callability cuts both ways: issuers can redeem these bonds at their option, capping price upside and forcing reinvestment at whatever rates exist that day.fminvest.com
• A 2025 launch that is still small and thinly traded. Short track record, and limit orders are the sane way in and out.

Full TAXS profile⁠

Full ZMUN profile⁠