Nuveen Municipal (NYSE: NMZ) insider Joseph Castro files initial Form 3

Rhea-AI Filing Summary

NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND reported an initial insider ownership filing for executive Joseph Castro. He serves as EVP, Chief Risk & Compliance. This Form 3 does not list any share transactions, functioning as a baseline disclosure of his reporting status with the fund.

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

Castro Joseph

(Last) (First) (Middle)

C/O NUVEEN INVESTMENTS

333 W. WACKER DRIVE

(Street)

CHICAGO IL 60606

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
10/16/2025

3. Issuer Name and Ticker or Trading Symbol
NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND [ NMZ ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Risk & Compliance

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

castropoa.txt

No securities are beneficially owned.

	Mark L. Winget/ Signed Under Power of Attorney	10/16/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What does the NMZ Form 3 filing for Joseph Castro report?

The NMZ Form 3 filing records Joseph Castro’s initial status as a reportable insider. It identifies him as an executive of Nuveen Municipal High Income Opportunity Fund, without listing any specific share transactions or changes in ownership in this filing.

What is Joseph Castro’s role at Nuveen Municipal High Income Opportunity Fund (NMZ)?

Joseph Castro is listed as an officer of Nuveen Municipal High Income Opportunity Fund, serving as EVP, Chief Risk & Compliance. This senior role places him under insider reporting requirements, which is why a Form 3 has been filed in his name.

Does the NMZ Form 3 for Joseph Castro show any stock purchases or sales?

The NMZ Form 3 for Joseph Castro shows no reported transactions. The transaction summary indicates zero buys, zero sells, zero acquisitions, and zero dispositions, meaning this filing is purely an initial ownership report rather than a record of trading activity.

Why is a Form 3 filed for an NMZ executive like Joseph Castro?

A Form 3 is filed when someone becomes an insider subject to reporting rules. For NMZ, it establishes Joseph Castro, EVP, Chief Risk & Compliance, as a reporting person whose future transactions in the fund’s securities must be disclosed in subsequent forms.

Does the NMZ Form 3 indicate net buying or selling activity by Joseph Castro?

No net buying or selling activity is indicated for Joseph Castro in the NMZ Form 3. The transaction summary shows neutral net direction with zero buy shares, zero sell shares, and no other categorized transactions reported in this initial statement.