Pioneer Municipal High Income Opportunities Fund, Inc.
MIOOther · MD · SEC filings ↗ · Compare ⊕
View price & chart on Yahoo Finance ↗Financials
SEC XBRL · annualNo structured XBRL financials available (common for pre-2009 filers, foreign issuers, or companies that never reported as a US public company).
5%+ owners
SEC Schedule 13D / 13G · last 3 yrs- Saba Capital Management, L.P.Activist (13D)Sep 2, 2025
- Rivernorth Capital Management, LlcPassive (13G)Aug 14, 2025
Holders who disclosed a 5%+ stake. 13D signals intent to influence or control; 13G is a passive holding. Latest filing per holder — open it for the exact stake.
Short interest
FINRA · bi-monthly| Settlement | Shares short | Days to cover | Δ vs prior |
|---|---|---|---|
| Aug 15, 2025 | 16,152 | 1.0 | -7.8% |
| Jul 31, 2025 | 17,519 | 1.0 | -8.2% |
| Jul 15, 2025 | 19,091 | 1.0 | +75.0% |
| Jun 30, 2025 | 10,911 | 1.0 | +85.2% |
| Jun 13, 2025 | 5,893 | 1.0 | -14.2% |
Shares sold short as reported to FINRA. Days-to-cover = short shares ÷ average daily volume — higher means more potential squeeze pressure.
Material events
SEC Form 8-K · most recent- Other material eventMay 20, 2025
- Amended charter or bylawsMay 9, 2025
- Other material eventMay 8, 2025
- Other material eventApr 2, 2025
- Other material eventMar 25, 2025
- Other material eventJul 19, 2024
Events the company reported on Form 8-K, labelled by the SEC item code it filed under — its own classification, not our interpretation.
Recent SEC filings
All filings ↗- 40-17GVP IV, VVIF II, ET AL - FIDELITY BOND 2026Apr 9, 2026
- NPORT-PApr 1, 2026
- N-CSRSPIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INCJan 6, 2026
- NPORT-PDec 19, 2025
- NPORT-PSep 26, 2025
- 4PRIMARY DOCUMENTSep 2, 2025
- SCHEDULE 13D/ASep 2, 2025
- N-PXAug 27, 2025
- 25-NSEAug 27, 2025
- SCHEDULE 13G/AAug 14, 2025
- N-CENJul 14, 2025
- N-CSRPIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC.Jul 9, 2025
- DEFA14AADDITIONAL DEFINITIVE PROXY MATERIALSJul 9, 2025
- NPORT-PJun 27, 2025
- DEF 14AJun 10, 2025