SUB vs TAXS

SUBAiShares Short-Term National Muni Bond ETF

TAXSANorthern Trust Short-Term Tax-Exempt Bond ETF

In short

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.

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.

Stated mandate

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.

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.

Why people hold it

• 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.

• 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

Worth knowing

• 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.

• 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

Full SUB profile⁠

Full TAXS profile⁠