Morgan Stanley and Parametric disclose HIO holdings (HIO) in Schedule 13G filings

Rhea-AI Filing Summary

WESTERN ASSET HIGH INCOME OPPORTUNITY FUND INC. Schedule 13G filings show Morgan Stanley and Parametric Portfolio Associates LLC reported beneficial ownership positions in the company's common stock. Morgan Stanley reports 5,853,092 shares (6.2%) with shared voting and dispositive powers; Parametric reports 5,469,095 shares (5.8%). The filings list CUSIP 95766K109 and are signed on 05/11/2026.

Insights

Institutional Ownership Analyst

Large institutional stakes disclosed by two asset managers.

These Schedule 13G filings report shared dispositive and shared voting powers for Morgan Stanley and Parametric, indicating passive investment reporting rather than activist intent. The filings list precise share counts and percentages useful for ownership concentration analysis.

Future proxy materials and periodic filings may show whether these holdings change; subsequent 13D or proxy disclosures would indicate active engagement.

Compliance & Filings Specialist

Filings follow Schedule 13G passive-investor format with joint filing exhibits.

The submission includes a Joint Filing Agreement (Exhibit 99.1) and Item 7 exhibit guidance (Exhibit 99.2). Signatures for both filers are dated 05/11/2026, and the cover-page entries list citizenship as Delaware.

These are administrative disclosures; any change in intent would require an amended filing or Schedule 13D.

Key Figures

Morgan Stanley shares: 5,853,092 shares Morgan Stanley percent: 6.2 % Parametric shares: 5,469,095 shares +3 more

6 metrics

Morgan Stanley shares 5,853,092 shares beneficially owned; shared dispositive power

Morgan Stanley percent 6.2 % percent of class reported

Parametric shares 5,469,095 shares beneficially owned; shared dispositive power

Parametric percent 5.8 % percent of class reported

CUSIP 95766K109 Common Stock identifier

Filing signatures 05/11/2026 signing date for both filers

Key Terms

Schedule 13G, beneficially owned, shared dispositive power, Joint Filing Agreement

4 terms

Schedule 13G regulatory

"Item 1. | (a) | Name of issuer: WESTERN ASSET HIGH INCOME OPPORTUNITY FUND"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

beneficially owned financial

"Item 4. | Ownership (a) | Amount beneficially owned: See the response(s) to Item 9"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

shared dispositive power financial

"8 | Shared Dispositive Power 5,853,092.00"

Joint Filing Agreement regulatory

"Exhibit 99.1 Joint Filing Agreement"

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Accepted by SEC EDGAR 05/11/2026 - 12:52 PM Learn about SEC filing dates

FAQ

What stake does Morgan Stanley report in HIO?

Morgan Stanley reports beneficial ownership of 5,853,092 shares (6.2%). The filing shows shared voting and shared dispositive powers and is dated 05/11/2026.

What stake does Parametric Portfolio Associates report in HIO?

Parametric reports beneficial ownership of 5,469,095 shares (5.8%). The filing lists Parametric's address as 800 Fifth Avenue, Suite 2800, Seattle, WA and is signed 05/11/2026.

Are these Schedule 13G filings passive or active disclosures for HIO?

These are Schedule 13G passive-investor disclosures filed jointly by Morgan Stanley and Parametric. The exhibits include a Joint Filing Agreement and Item 7 information referenced in the cover pages.

What CUSIP and class are reported in the filings for HIO?

The filings report the company's common stock with CUSIP 95766K109. The class of securities is explicitly listed as Common Stock in Item 2(d).

When were the Schedule 13G forms signed for HIO?

Both filings are signed on 05/11/2026. Signatories listed are Claire Gordon for Morgan Stanley and Cindy Kim for Parametric Portfolio Associates LLC.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

WESTERN ASSET HIGH INCOME OPPORTUNITY FUND INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

95766K109

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 95766K109

1

Names of Reporting Persons

Morgan Stanley

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,071,311.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,853,092.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,853,092.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.2 %

12

Type of Reporting Person (See Instructions)

HC, CO

SCHEDULE 13G

CUSIP Number(s): 95766K109

1

Names of Reporting Persons

Parametric Portfolio Associates LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 687,314.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,469,095.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,469,095.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.8 %

12

Type of Reporting Person (See Instructions)

IA, CO

SCHEDULE 13G

Item 1.
(a)	Name of issuer: WESTERN ASSET HIGH INCOME OPPORTUNITY FUND INC.
(b)	Address of issuer's principal executive offices: 620 EIGHTH AVENUE, 47TH FLOOR, NEW YORK, NY, 10018
Item 2.
(a)	Name of person filing: 1: Morgan Stanley 2: Parametric Portfolio Associates LLC
(b)	Address or principal business office or, if none, residence: 1: 1585 Broadway, New York, NY 10036 ;2: 800 Fifth Avenue, Suite 2800, Seattle, WA 98104
(c)	Citizenship: 1: Delaware 2: Delaware
(d)	Title of class of securities: Common Stock
(e)	CUSIP Number(s): 95766K109
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: See the response(s) to Item 9 on the attached cover page(s).
(b)	Percent of class: 6.2 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See the response(s) to Item 5 on the attached cover page(s).
	(ii) Shared power to vote or to direct the vote: See the response(s) to Item 6 on the attached cover page(s).
	(iii) Sole power to dispose or to direct the disposition of: See the response(s) to Item 7 on the attached cover page(s).
	(iv) Shared power to dispose or to direct the disposition of: See the response(s) to Item 8 on the attached cover page(s).
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit 99.2
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. * In Accordance with the Securities and Exchange Commission Release No. 34-39538 (January 12, 1998) (the "Release"), this filing reflects the securities beneficially owned, or that may be deemed to be beneficially owned, by certain operating units (collectively, the "MS Reporting Units") of Morgan Stanley and its subsidiaries and affiliates (collectively, "MS"). This filing does not reflect securities, if any, beneficially owned by any operating units of MS whose ownership of securities is disaggregated from that of the MS Reporting Units in accordance with the Release.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Morgan Stanley

Signature:	Claire Gordon
Name/Title:	Authorized Signatory, Morgan Stanley
Date:	05/11/2026

Parametric Portfolio Associates LLC

Signature:	Cindy Kim
Name/Title:	Authorized Signatory, Parametric Portfolio Associates LLC
Date:	05/11/2026

Exhibit Information

EXHIBIT NO. EXHIBITS ------------------ ------------------------------------ 99.1 Joint Filing Agreement 99.2 Item 7 Information * Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001).