What Is SUB? iShares Short-Term National Muni Bond ETF

SUB is iShares Short-Term National Muni Bond ETF, an ETF that tracks a short-duration national municipal bond index at a 0.07% expense ratio. SUB holds short-duration national municipal bonds, bundled into one ticker. It distributes about 2.52%, and that payout moves with rates rather than being fixed. It launched in 2008. It charges 0.07%.

SUB is issued by iShares and tracks a short-duration national municipal bond index, so a single ticker gives you the whole portfolio of underlying holdings weighted by the index's methodology rather than by any active stock-picking.

SUB does not hold a basket of individual stocks. It gets its exposure synthetically, through derivatives such as swaps and futures rather than by owning the underlying shares, so there is no conventional top-10 equity holdings list. See the description above for what SUB actually tracks and how that exposure is built.

There are three common ways to get SUB exposure. Buy shares (or fractional shares) of SUB directly at any major broker that lists it. Hold it as a core position and layer more concentrated ideas on top. Or build it into a thematic portfolio in Walnut, so SUB sits alongside other holdings that express the same thesis, with target weights you can rebalance toward. SUB trades like a stock during market hours, so you buy it the same way you would any listed share.

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Whether SUB is a good buy depends less on any single call and more on your time horizon and what you already hold: it tracks a short-duration national municipal bond index, so the real question is whether you want that exposure in your mix and at what weight. We walk through valuation, concentration, and what would have to be true for it to outperform from here in is SUB a buy?

SUB gives you a short-duration national municipal bond index exposure in one ticker at a 0.07% expense ratio. Most investors use it as a core holding and layer more concentrated thematic portfolios on top.

Whether SUB is worth buying today depends more on your time horizon and what you already hold than on any single call. We walk through valuation, concentration, and what would have to be true for it to outperform from here in is SUB a buy?

SUB yields 2.52% as of August 2026, paid by passing through the dividends of its underlying holdings. For the payout schedule, history, and how the distributions are taxed, see SUB dividend: yield and schedule.

New to funds like SUB? Start with what an ETF is, then how to buy an ETF, or browse the full guide to ETF investing.