Company: NMZ
Filing Date: 2025-07-07
Form Type: N-CSRS
Source: 0001193125-25-156000
Chunk: 10

Company: NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND
Filing Date: 2025-07-07
Form: N-CSRS
Chunk 10
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, which 
 ensure the timely payment of principal and interest.                                                           |

| (f) | Floating or variable rate security includes the reference rate and spread, unless the variable rate is based on the 
 underlying asset of the security. Coupon rate reflects the rate at period end.                                      |

| (g) | Step-up coupon bond, a bond with a coupon that increases (“steps                                                                       
 up”), usually at regular intervals, while the bond is outstanding. The rate shown is the coupon as of the end of the reporting period. |

| (h) | Inverse floating rate trust is a non recourse trust. |

| (i) | MFP Shares, Net as a percentage of Total Investments is 15.9%. |

| (j) | VRDP Shares, Net as a percentage of Total Investments is 16.8%. |

| See Notes to Financial Statements |     | 91 |

Portfolio of Investments April 30, 2025 NMZ (Unaudited)

| SHARES    |            |     |        |     | DESCRIPTION                                                                                                                                                                         
 LONG-TERM INVESTMENTS - 162.7% (100.0% of Total Investments)                                                                                                                        
 COMMON STOCKS - 0.0% (0.0% of Total Investments)                                                                                                                                    
 MATERIALS - 0.0% (0.0% of Total Investments)                                                                                                                                        |     |      |        |     |          |          |     | VALUE |            |
|:----------|-----------:|:----|:-------|:----|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:----|:-----|-------:|:----|:---------|:---------|:----|:------|-----------:|
|           |         39 |     | -a),(b |     | PALOUSE FIBER HOLDINGS                                                                                                                                                              |     |      |        |     |          |          |     | $     |          0 |
|           |            |     |        |     | TOTAL MATERIALS                                                                                                                                                                     |     |      |        |     |          |          |     |       |          0 |
|           |            |     |        |     | TOTAL COMMON STOCKS                                                                                                                                                                 
 (Cost $5,850)                                                                                                                                                                       |     |      |        |     |          |          |     |       |          0 |
| SHARES    |            |     |        |     | DESCRIPTION                                                                                                                                                                         |     |      |        |     |          |          |     | VALUE |            |