Bulldog Investors reports 12.93% CMU stake; 3,295,118 shares

Rhea-AI Filing Summary

Bulldog Investors, Phillip Goldstein, and Andrew Dakos updated their ownership in MFS High Yield Municipal Trust (CMU) via Schedule 13D/A (Amendment No. 8). The filing bases percentages on 25,492,782 shares outstanding as of 5/31/2025, per an N-CSRS.

As of 11/12/2025, Bulldog Investors is deemed the beneficial owner of 3,295,118 shares, representing 12.93%. Phillip Goldstein is deemed the beneficial owner of 3,631,503 shares (14.25%), and Andrew Dakos is deemed the beneficial owner of 3,185,308 shares (12.49%).

Bulldog has sole voting/dispositive power over 109,810 shares and shared power over 3,185,308 shares. Goldstein has sole power over 109,810 shares and shared power over 3,521,693 shares; Dakos has shared power over 3,185,308 shares. Recent activity includes multiple trades, such as 35,000 shares at $3.5172 on 11/12/2025.

Insights

Closed-end fund governance analyst

Ownership updated; stakes exceed 10%, signaling influence but no new actions.

The amendment reports sizable beneficial ownership in CMU by Bulldog Investors and its principals. Percentages are calculated from 25,492,782 shares outstanding as of 5/31/2025. Stakes of 12.93% (Bulldog), 14.25% (Goldstein), and 12.49% (Dakos) indicate meaningful voting power within a closed-end fund structure.

The filing details voting and dispositive powers, clarifying who can direct votes and sales. It also lists recent trades, including $3.5172 for 35,000 shares on 11/12/2025. The update itself does not announce strategic actions; actual impact depends on future disclosures or proposals.

Key details to track in subsequent materials would be any changes to ownership levels or stated intentions, as none are specified in this excerpt.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 8)

MFS High Yield Municipal Trust

(Name of Issuer)

Common Stock

(Title of Class of Securities)

59318E102

(CUSIP Number)

Phillip Goldstein
250 Pehle Ave., Suite 708
Saddle Brook, NJ, 07663
914 747-5262

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

11/12/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 59318E102

1

Name of reporting person

Bulldog Investors, LLP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 109,810.00
8	Shared Voting Power 3,185,308.00
9	Sole Dispositive Power 109,810.00
10	Shared Dispositive Power 3,185,308.00

11

Aggregate amount beneficially owned by each reporting person

3,295,118.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

12.93 %

14

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13D

CUSIP No. 59318E102

1

Name of reporting person

Phillip Goldstein

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 109,810.00
8	Shared Voting Power 3,521,693.00
9	Sole Dispositive Power 109,810.00
10	Shared Dispositive Power 3,521,693.00

11

Aggregate amount beneficially owned by each reporting person

3,631,503.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

14.25 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP No. 59318E102

1

Name of reporting person

Andrew Dakos

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,185,308.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,185,308.00

11

Aggregate amount beneficially owned by each reporting person

3,185,308.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

12.49 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock
(b)	Name of Issuer: MFS High Yield Municipal Trust
(c)	Address of Issuer's Principal Executive Offices: 111 Huntington Avenue, 24TH FLOOR, Boston, MASSACHUSETTS , 02199.
Item 1 Comment: This Constitutes Amendment #8 to the schedule 13D filed July 17, 2023. Except as specifically set forth herein, the schedule 13D rmains unmodified.
Item 5.	Interest in Securities of the Issuer
(a)	As per the N-CSRS filed on 7/28/25 there were 25,492,782 shares of common stock outstanding as of 5/31/25. The percentages set forth herein were derived using such number. Phillip Goldstein and Andrew Dakos own Bulldog Investors, LLP, a registered investment advisor. As of November 12 2025, Bulldog Investors, LLP is deemed to be the beneficial owner of 3,295,118 shares of CMU (representing 12.93% of CMU's outstanding shares) soley by virtue of Bulldog Investors, LLP's power to direct the vote of, and dispose of, these shares. As of November 12 2025, Mr. Goldstein is deemed to be the beneficial owner of 3,631,503 shares of CMU (representing 14.25% of CMU's outstanding shares) and Mr. Dakos is deemed to be the beneficial owner of 3,185,308 shares of CMU (representing 12.49% of CMU's outstanding shares) by virtue of their power to direct the vote of, and dispose of, these shares.
(b)	Bulldog Investors, LLP has sole power to dispose of and vote 109,810 shares. Bulldog Investors, LLP has shared power to dispose and vote 3,185,308 shares. Certain of Bulldog Investors, LLP's clients (none of whom beneficially own more than 5% of CMU's shares) share this power with Bulldog Investors. Messrs. Goldstein and Dakos are partners of Bulldog Investors, LLP.
(c)	During the last 60 days the following shares of CMU were purchased or sold. Date Shares Price 11/12/2025 35,000 3.5172 11/11/2025 45,000 3.5200 11/07/2025 20,000 3.5100 11/06/2025 11,500 3.5194 11/04/2025 10,272 3.5083 11/03/2025 10,000 3.5000 10/30/2025 12,870 3.5100 10/29/2025 2,062 3.5100 10/16/2025 20,000 3.4800 10/16/2025 (5,000) 3.4700 10/10/2025 6,744 3.4700 10/06/2025 600 3.4400 10/03/2025 1,102 3.4400 10/01/2025 20,000 3.4599 9/29/2025 218 3.4300 9/23/2025 100 3.4500 9/22/2025 1,041 3.4500 9/19/2025 9,800 3.4400 9/18/2025 16,795 3.4500 9/17/2025 800 3.4400 7/17/2025 16,625 3.2361
(d)	Clients of Bulldog Investors, LLP and the owners of accounts reflected herein are entitled to receive any dividends or sales proceeds.

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.

Bulldog Investors, LLP

Signature:	/s/ Andrew Dakos
Name/Title:	Andrew Dakos, Partner
Date:	11/13/2025

Phillip Goldstein

Signature:	/s/ Phillip Goldstein
Name/Title:	Phillip Goldstein
Date:	11/13/2025

Andrew Dakos

Signature:	/s/ Andrew Dakos
Name/Title:	Andrew Dakos
Date:	11/13/2025

FAQ

What did Bulldog Investors disclose about CMU (ticker: CMU)?

They filed Amendment No. 8 to Schedule 13D, updating beneficial ownership and voting/dispositive powers in MFS High Yield Municipal Trust.

How many CMU shares and what percent does Phillip Goldstein report?

Phillip Goldstein is deemed the beneficial owner of 3,631,503 shares, representing 14.25% as of 11/12/2025.

What is Bulldog Investors’ reported stake in CMU?

Bulldog Investors reports 3,295,118 shares, or 12.93%, as of 11/12/2025.

What baseline share count was used to calculate the percentages?

Percentages were derived from 25,492,782 shares outstanding as of 5/31/2025, cited from an N-CSRS.

What recent transactions were reported in the last 60 days?

The filing lists multiple trades, including 35,000 shares at $3.5172 on 11/12/2025 and other purchases in October–November 2025.

Who holds voting and dispositive power over the CMU shares?

Bulldog has sole power over 109,810 shares and shared power over 3,185,308; Goldstein has sole 109,810 and shared 3,521,693; Dakos has shared 3,185,308.

Who signed the amendment and when?

The amendment was signed by Andrew Dakos and Phillip Goldstein on 11/13/2025.