Investors in the top federal tax bracket who hold corporate bond funds can lose a large portion of their yield to taxes before they see a dollar of income. One actively managed ETF is built specifically to exploit that gap.
What Problem This ETF Solves
iShares High Yield Muni Active ETF (CBOE:HIMU) is not a conventional bond fund. It converted from a mutual fund to an ETF structure on February 7, 2025, lowering the cost of entry while preserving the same active management strategy that has run the underlying portfolio for years. The fund’s mission is straightforward: deliver as much federal tax-exempt income as possible while managing credit risk through active security selection rather than passive index replication.
The tax math is compelling. The fund’s 30-day SEC yield of about 5.2% translates to a tax-equivalent yield of nearly 8.8% for investors in the highest tax brackets, meaning a taxable bond fund would need to yield nearly 8.77% just to match HIMU on an after-tax basis. Most investment-grade corporate bond ETFs are yielding well below that threshold right now.
How the Return Engine Works
Income comes from two sources: the tax exemption on municipal bond interest, and a deliberate tilt toward lower-rated and unrated bonds that carry higher coupons. The fund holds 894 positions, with 57% of the portfolio in unrated securities, a level of credit complexity that most passive muni index funds avoid. That’s where active management earns its keep: identifying credits that carry higher yields without proportionate default risk.
The net expense ratio is about 0.4%, with a fee waiver in place through June 30, 2026, keeping costs lean for an actively managed fund. Monthly distributions have been consistent, with 2026 payments ranging between roughly $0.20 and $0.24 per share. The income stream is predictable enough to plan around, though individual monthly amounts fluctuate.
Does It Actually Deliver?
On total return, HIMU has been steady rather than spectacular. Over the past year, the fund returned about 7%, and year-to-date through early April 2026, it is up roughly 1%. The fund returned about 3% in 2025 despite broader market headwinds. These are not numbers that will make headlines next to an equity fund, but they are also not the right comparison. The relevant benchmark is a taxable bond fund generating similar headline yield, after taxes, with similar volatility.
Stability matters. The fund carries an equity beta of about 0.5 relative to the S&P 500, meaning it moves at roughly half the pace of the stock market during broad selloffs. Effective duration sits at about 9.6 years, which is meaningfully long and makes the fund sensitive to rising interest rates, but also positions it to benefit when rates fall.
The Tradeoffs Worth Understanding
Three constraints define who this fund works for.
- Duration risk is real. A 9.6-year effective duration means a 1% rise in interest rates could reduce the fund’s price by roughly 9%. Investors who need capital stability in the short term should weigh this carefully before treating HIMU as a cash substitute.
- The tax advantage only matters if you have taxable income to shelter. Investors holding this fund inside a traditional IRA or 401(k) receive no benefit from the tax exemption, effectively turning a tax-advantaged strategy into a lower-yielding bond fund. HIMU belongs in a taxable brokerage account.
- Credit complexity requires trust in the manager. With more than half the portfolio in unrated bonds, investors are relying on BlackRock’s research team to identify credits that are safe despite lacking agency ratings. That’s a reasonable bet given the team’s resources, but it is a different kind of risk than holding an investment-grade index fund.
For investors in the 32% federal bracket or above holding HIMU in a taxable brokerage account, the combination of tax-exempt monthly income and active credit management addresses a gap that passive corporate bond funds cannot fill.
