# Nuveen Municipal High Income Opportunity Fund: filings

NMZ · NYSE · CIK 1266585 · [Other](/sectors/other.md)

Pages: [Overview](/companies/nmz.md) · [Financials](/companies/nmz/financials.md) · [Filings](/companies/nmz/filings.md) · [Insiders](/companies/nmz/insiders.md)

## Reports and events: 28 filings

Newest first, by EDGAR acceptance time (Eastern). Filter with ?form= one of: `periodic`, `8-K`, `10-K`, `10-Q`, `4`, `proxy`, `13dg`, `all`, or any form this company filed (3 55, 425 30, NPORT-P 28, 4 26, N-Q 21, CORRESP 19, N-CSR 18, N-CSRS 18, N-PX 18, DEF 14A 17, 424B3 12, 497 12, EFFECT 10, N-2/A 10, N-23C-2 9, NSAR-A 9, NSAR-B 9, N-CEN 8, POS 8C 8, 486BPOS 6, POS EX 6, 497J 5, 8-K 5, N-2 5, AW 4, PRE 14A 4, SC 13G/A 4, 424B5 3, DEFA14A 3, N-14 8C/A 3, SC 13D 3, SC 13D/A 3, N-14 8C 2, N-2ASR 2, SC 13G 2, 144 1, 25 1, 424B2 1, 497AD 1, 8-A12B 1, AW WD 1, CERTNYS 1, N-CEN/A 1, NO ACT 1, NPORT-EX 1, N-PX/A 1, UPLOAD 1).

| Filed | Accepted | Form | What it is | Accession |
| --- | --- | --- | --- | --- |
| 2026-07-02 | 01:19 ET | [DEF 14A](/filings/0001193125-26-293122.md) | Proxy statement, period 2026-08-13 | 0001193125-26-293122 |
| 2025-06-30 | 20:29 ET | [DEF 14A](/filings/0001193125-25-152769.md) | Proxy statement, period 2025-08-14 | 0001193125-25-152769 |
| 2024-06-27 | 21:27 ET | [DEF 14A](/filings/0001193125-24-170731.md) | Proxy statement, period 2024-08-08 | 0001193125-24-170731 |
| 2024-03-06 | 20:15 ET | [8-K](/filings/0001193125-24-060622.md) | 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0001193125-24-060622 |
| 2023-10-13 | 11:37 ET | [8-K](/filings/0001193125-23-255708.md) | 5.02 Departure or appointment of officers or directors | 0001193125-23-255708 |
| 2023-06-30 | 20:55 ET | [DEF 14A](/filings/0001193125-23-180540.md) | Proxy statement, period 2023-08-09 | 0001193125-23-180540 |
| 2023-04-26 | 20:12 ET | [SC 13D/A](/filings/0001193125-23-118529.md) | Ownership report, active investor, amended | 0001193125-23-118529 |
| 2023-04-05 | 20:31 ET | [SC 13D/A](/filings/0001193125-23-092341.md) | Ownership report, active investor, amended | 0001193125-23-092341 |
| 2022-06-28 | 20:33 ET | [DEF 14A](/filings/0001193125-22-183966.md) | Proxy statement, period 2022-08-05 | 0001193125-22-183966 |
| 2022-06-13 | 19:50 ET | [SC 13D/A](/filings/0001193125-22-172872.md) | Ownership report, active investor, amended | 0001193125-22-172872 |
| 2022-02-25 | 12:13 ET | [8-K](/filings/0001193125-22-053235.md) | 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0001193125-22-053235 |
| 2021-06-25 | 21:22 ET | [DEF 14A](/filings/0001193125-21-200611.md) | Proxy statement, period 2021-08-04 | 0001193125-21-200611 |
| 2021-04-28 | 17:34 ET | [SC 13D](/filings/0001193125-21-136356.md) | Ownership report, active investor | 0001193125-21-136356 |
| 2020-10-06 | 00:09 ET | [8-K](/filings/0001193125-20-264158.md) | 7.01 Regulation FD disclosure; 9.01 Financial statements and exhibits | 0001193125-20-264158 |
| 2020-06-26 | 19:07 ET | [DEF 14A](/filings/0001193125-20-180767.md) | Proxy statement, period 2020-08-05 | 0001193125-20-180767 |
| 2019-06-28 | 18:28 ET | [DEF 14A](/filings/0001193125-19-185727.md) | Proxy statement, period 2019-08-07 | 0001193125-19-185727 |
| 2018-06-28 | 20:51 ET | [DEF 14A](/filings/0001193125-18-207747.md) | Proxy statement, period 2018-08-08 | 0001193125-18-207747 |
| 2017-06-23 | 14:07 ET | [DEF 14A](/filings/0001193125-17-211195.md) | Proxy statement, period 2017-08-02 | 0001193125-17-211195 |
| 2016-08-05 | 18:13 ET | [8-K](/filings/0001193125-16-673253.md) | 8.01 Other events | 0001193125-16-673253 |
| 2016-06-24 | 21:23 ET | [DEF 14A](/filings/0001193125-16-631693.md) | Proxy statement, period 2016-08-03 | 0001193125-16-631693 |
| 2015-07-01 | 21:47 ET | [DEF 14A](/filings/0001193125-15-241551.md) | Proxy statement, period 2015-08-05 | 0001193125-15-241551 |
| 2013-04-25 | 20:08 ET | [DEF 14A](/filings/0001193125-13-173695.md) | Proxy statement, period 2013-05-16 | 0001193125-13-173695 |
| 2012-12-28 | 16:43 ET | [SC 13D](/filings/0000070858-12-000410.md) | Ownership report, active investor | 0000070858-12-000410 |
| 2012-07-02 | 19:27 ET | [DEF 14A](/filings/0001193125-12-291895.md) | Proxy statement, period 2012-07-31 | 0001193125-12-291895 |
| 2011-06-22 | 20:20 ET | [DEF 14A](/filings/0000950123-11-060824.md) | Proxy statement, period 2011-07-25 | 0000950123-11-060824 |
| 2010-08-05 | 15:23 ET | [SC 13D](/filings/0001048703-10-000134.md) | Ownership report, active investor | 0001048703-10-000134 |
| 2010-06-18 | 17:29 ET | [DEF 14A](/filings/0000950123-10-059234.md) | Proxy statement, period 2010-07-27 | 0000950123-10-059234 |
| 2009-06-18 | 15:51 ET | [DEF 14A](/filings/0000950123-09-014924.md) | Proxy statement, period 2009-07-28 | 0000950123-09-014924 |

Source: SEC EDGAR, the company’s filing index. Last ingested by Listed: Oct 24, 2026, 15:10 ET. No prices; not investment advice.