Nuveen Municipal High Income Opportunity Fund
Actively managed U.S. bond closed-end fund
As of its 2026 Q2 report, Nuveen Municipal High Income Opportunity Fund held 1,470 positions with $2.23B in net assets. Its ten largest holdings made up 11.2% of the fund. Over the 12 months to May 2026, NMZ returned 9.3%, with dividends reinvested. In 2026 Q3 it added 145 new positions and exited 151.
Nuveen Municipal High Income Opportunity Fund is actively managed U.S. bond closed-end fund.
What you own
| Company | Weight | Value | Shares | Reported price |
|---|---|---|---|---|
Puerto Rico Sales Tax Financing Corporation, Sales Tax Revenue Bonds, Restructured 2018A-1 0.00% · due 2051-07-01 | 1.86% | $41.59M | — | — |
New Jersey Transportation Trust Fund Authority, Transportation System Bonds, Refunding Series 2006C 0.00% · due 2032-12-15 | 1.34% | $30.01M | — | — |
New Jersey Transportation Trust Fund Authority, Transportation System Bonds, Refunding Series 2006C 0.00% · due 2033-12-15 | 1.33% | $29.63M | — | — |
New Jersey Transportation Trust Fund Authority, Transportation System Bonds, Refunding Series 2006C 0.00% · due 2035-12-15 | 1.28% | $28.61M | — | — |
New Jersey Transportation Trust Fund Authority, Transportation System Bonds, Capital Appreciation Series 2010A 0.00% · due 2030-12-15 | 1.21% | $27.08M | — | — |
State Public School Building Authority, Pennsylvania, Lease Revenue Bonds, Philadelphia School District, Series 2003 5.50% · due 2028-06-01 | 0.99% | $22.13M | — | — |
Iowa Finance Authority, Iowa, Midwestern Disaster Area Revenue Bonds, Iowa Fertilizer Company Project, Refunding Series 2022 5.00% · due 2050-12-01 | 0.91% | $20.31M | — | — |
Kentucky Economic Development Finance Authority, Hospital Revenue Bonds, Owensboro Health, Refunding Series 2017A 5.00% · due 2041-06-01 | 0.77% | $17.17M | — | — |
New York Transportation Development Corporation, New York, Special Facilities Bonds, LaGuardia Airport Terminal B Redevelopment Project, Series 2016A 5.25% · due 2050-01-01 | 0.76% | $16.99M | — | — |
Nuveen High Yield Municipal Bond ETF | 0.75% | $16.84M | 675.0K | $24.95 |
Reported price is the fund's own reported value divided by its own reported shares at 2026-04-30 — not a live quote, and not what the fund paid.
The 200 largest of 1,470 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Bonds | 159.95% |
| Stocks | 0.75% |
| Derivatives | 0.00% |
These positions come to 160.70% of the fund's net assets. This counts only what the fund reported holding — the holdings disclosure covers assets, not liabilities such as borrowings — so it is not expected to reconcile to 100%.
Derivatives are shown at market value, not notional exposure.
How it has done
NMZ share class · total returns with dividends reinvested
Volatility over the last 12 months: 7.97%. Past returns are a record, not a forecast.
Jun 2026 and Jul 2026 have been filed since the trailing figures were struck, so they are not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.
Fees & fund details
Nuveen Municipal High Income Opportunity Fund is an actively managed U.S. bond closed-end fund.
- Asset class
- Bonds
- Region
- United States
- Management
- Actively managed
- Fund type
- Closed-end fund
- Credit quality
- Mixed credit
- Rate sensitivity
- Long duration
This fund files no prospectus profile. Unit investment trusts and closed-end funds register on forms that carry no objective or fee tagging, and some fund families file without it — a gap in what was filed, not a fund without an objective or without fees.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
145 new· the largest 8
151 exited· the largest 8
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-04-30
Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.
| Fixed rate | 98.1% |
| Floating rate | 1.9% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 1.3% |
| 1-3y | 1.1% |
| 3-5y | 2.0% |
| 5-10y | 9.7% |
| 10y+ | 85.8% |
These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.
Risk profile
Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2
Most of this fund’s sensitivity is to interest rates, with credit spreads carrying nearly as much.
Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.
| Interest rates | 53% |
| Credit spreads | 47% |
Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.
Share of the fund's spread duration carried by each credit tier.
| Investment grade | +7.52 yr |
| High yield | +4.61 yr |
Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.
| 3 mo | 0.18 yr | 1% |
| 1 yr | 0.65 yr | 5% |
| 5 yr | 2.03 yr | 15% |
| 10 yr | 6.31 yr | 46% |
| 30 yr | 4.53 yr | 33% |
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.05 yr | 0% |
| 5 yr | 0.42 yr | 3% |
| 10 yr | 3.54 yr | 29% |
| 30 yr | 8.11 yr | 67% |
The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.
Show the numbers
| Tenor | Rate yrs | IG yrs | HY yrs | IG $/bp | HY $/bp |
|---|---|---|---|---|---|
| 3 mo | +0.18 | +0.01 | +0.00 | $1.6k | $185 |
| 1 yr | +0.65 | +0.05 | +0.00 | $10.3k | $975 |
| 5 yr | +2.03 | +0.37 | +0.05 | $83.0k | $10.7k |
| 10 yr | +6.31 | +2.51 | +1.03 | $560.6k | $230.1k |
| 30 yr | +4.53 | +4.58 | +3.53 | $1.02m | $787.2k |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
A newer credit-spread reading (2026Q3) is on file. This page holds one quarter across every figure on it, so that one appears here next quarter.
Understand how this fund fits with the rest.
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