Browse the latest SEC filings and forms submitted by Pioneer Municipal High Income Opportunities Fund, Inc. (MIO). Access annual reports, quarterly statements, and other official disclosures.
View Insider Transactions for Pioneer Municipal High Income Opportunities Fund, Inc. (MIO).
Search Company Filings →| Form | Filing Date | Description | Link |
|---|---|---|---|
| SCHEDULE 13G/A | Aug. 14, 2025 | - | View Document |
| N-CEN | July 14, 2025 | - | View Document |
| N-CSR | July 9, 2025 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | June 27, 2025 | - | View Document |
| 4 | May 8, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | May 1, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | April 24, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | April 22, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | April 14, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | April 10, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | April 8, 2025 | PRIMARY DOCUMENT | View Document |
| 3 | April 4, 2025 | PRIMARY DOCUMENT | View Document |
| NPORT-P | March 25, 2025 | - | View Document |
| DFAN14A | Feb. 24, 2025 | - | View Document |
| SCHEDULE 13G | Feb. 14, 2025 | - | View Document |
| DEFC14A | Feb. 11, 2025 | MIO | View Document |
| DEFC14A | Feb. 10, 2025 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| SCHEDULE 13D/A | Feb. 4, 2025 | - | View Document |
| 4 | Feb. 3, 2025 | PRIMARY DOCUMENT | View Document |
| PRRN14A | Jan. 31, 2025 | - | View Document |
| PREC14A | Jan. 29, 2025 | MIO | View Document |
| 4 | Jan. 29, 2025 | PRIMARY DOCUMENT | View Document |
| SCHEDULE 13D/A | Jan. 28, 2025 | - | View Document |
| 4 | Jan. 27, 2025 | PRIMARY DOCUMENT | View Document |
| PREC14A | Jan. 24, 2025 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| 4 | Jan. 23, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | Jan. 21, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | Jan. 14, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | Jan. 10, 2025 | PRIMARY DOCUMENT | View Document |
| 4 | Jan. 6, 2025 | PRIMARY DOCUMENT | View Document |
| N-CSRS | Jan. 3, 2025 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC | View Document |
| 4 | Dec. 31, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Dec. 27, 2024 | PRIMARY DOCUMENT | View Document |
| SCHEDULE 13D/A | Dec. 23, 2024 | - | View Document |
| 4 | Dec. 23, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Dec. 19, 2024 | PRIMARY DOCUMENT | View Document |
| NPORT-P | Dec. 19, 2024 | - | View Document |
| 4 | Dec. 16, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Dec. 12, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 29, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 26, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 25, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 21, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 18, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 14, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 12, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 5, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Nov. 4, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Oct. 31, 2024 | PRIMARY DOCUMENT | View Document |
| DEFA14A | Oct. 22, 2024 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | Sept. 23, 2024 | - | View Document |
| 4 | Aug. 29, 2024 | PRIMARY DOCUMENT | View Document |
| N-PX | Aug. 28, 2024 | - | View Document |
| 4 | Aug. 27, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Aug. 23, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Aug. 22, 2024 | PRIMARY DOCUMENT | View Document |
| SC 13D/A | Aug. 21, 2024 | FORM SC 13D/A | View Document |
| DEFC14A | Aug. 19, 2024 | MIO | View Document |
| 4 | Aug. 15, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Aug. 13, 2024 | PRIMARY DOCUMENT | View Document |
| PREC14A | Aug. 9, 2024 | MIO | View Document |
| 4 | Aug. 8, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | Aug. 6, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | July 15, 2024 | PRIMARY DOCUMENT | View Document |
| N-CEN | July 12, 2024 | - | View Document |
| N-CSR | July 8, 2024 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | June 27, 2024 | - | View Document |
| 4 | May 31, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | May 17, 2024 | PRIMARY DOCUMENT | View Document |
| SC 13D/A | April 1, 2024 | FORM SC 13D/A | View Document |
| NPORT-P | March 21, 2024 | - | View Document |
| 3 | March 21, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | March 20, 2024 | PRIMARY DOCUMENT | View Document |
| CORRESP | March 19, 2024 | - | View Document |
| 4 | March 11, 2024 | PRIMARY DOCUMENT | View Document |
| 3 | March 6, 2024 | PRIMARY DOCUMENT | View Document |
| 3 | March 6, 2024 | PRIMARY DOCUMENT | View Document |
| 4 | March 6, 2024 | PRIMARY DOCUMENT | View Document |
| 3 | Jan. 30, 2024 | PRIMARY DOCUMENT | View Document |
| SC 13D | Jan. 5, 2024 | FORM SC 13D | View Document |
| N-CSRS | Jan. 3, 2024 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC | View Document |
| NPORT-P | Dec. 20, 2023 | - | View Document |
| N-CEN/A | Oct. 25, 2023 | - | View Document |
| NPORT-P | Sept. 26, 2023 | - | View Document |
| 3 | Sept. 5, 2023 | PRIMARY DOCUMENT | View Document |
| N-PX | Aug. 28, 2023 | FORM N-PX | View Document |
| N-CEN | July 13, 2023 | - | View Document |
| N-CSR | July 7, 2023 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC | View Document |
| NPORT-P | June 22, 2023 | - | View Document |
| NPORT-P | March 22, 2023 | - | View Document |
| SC 13G/A | Feb. 14, 2023 | FORM SC 13G/A | View Document |
| SC 13G | Feb. 13, 2023 | - | View Document |
| N-CSRS | Jan. 4, 2023 | PIONEER MUNICPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | Dec. 21, 2022 | - | View Document |
| SC 13G | Nov. 22, 2022 | FORM SC 13G | View Document |
| NPORT-P | Sept. 23, 2022 | - | View Document |
| N-PX | Aug. 29, 2022 | N-PX | View Document |
| N-CEN | July 12, 2022 | - | View Document |
| N-CSR | July 1, 2022 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | June 23, 2022 | - | View Document |
| NPORT-P | March 30, 2022 | - | View Document |
| N-CSRS | Jan. 3, 2022 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| NPORT-P | Dec. 23, 2021 | - | View Document |
| 3 | Sept. 20, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 20, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 20, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 18, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 16, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 10, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 10, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 10, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 10, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 10, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 3 | Aug. 9, 2021 | PRIMARY DOCUMENT | View Document |
| 424B1 | Aug. 6, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| EFFECT | Aug. 5, 2021 | - | View Document |
| N-2/A | Aug. 4, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| CORRESP | Aug. 3, 2021 | - | View Document |
| CORRESP | Aug. 3, 2021 | - | View Document |
| CERT | Aug. 3, 2021 | NYSE CERTIFICATION | View Document |
| 8-A12B | Aug. 3, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| N-2/A | July 28, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| N-2/A | July 26, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| CORRESP | July 23, 2021 | - | View Document |
| N-2/A | July 13, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| CORRESP | July 13, 2021 | - | View Document |
| UPLOAD | July 1, 2021 | - | View Document |
| N-2 | May 26, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |
| N-8A | May 26, 2021 | PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. | View Document |