Marathon Bancorp (MBBC) director exercises stock options and boosts trust holdings

Rhea-AI Filing Summary

Marathon Bancorp director Thomas L. Grimm exercised stock options to acquire additional common shares through a trust. On March 20, 2026, options covering 3,599 shares of common stock were exercised at $8.13 per share and 599 shares at $6.48 per share, increasing indirect holdings "By Trust" to 21,994 shares.

Following these transactions, Grimm also holds 2,998 shares directly. The options and related restricted stock and option awards vest at a rate of 20% per year starting on June 28, 2023 and May 16, 2024, indicating these are compensation-related equity grants becoming exercisable over time rather than open-market purchases.

Insights

Equity Compensation & Governance Analyst

Director exercised vested options to increase indirect share ownership via a trust; no sales occurred.

Director Thomas L. Grimm exercised stock options in Marathon Bancorp, Inc., converting derivatives into 3,599 and 599 common shares at exercise prices of $8.13 and $6.48. The resulting shares are held indirectly by a trust, with indirect ownership rising to 21,994 shares and direct holdings at 2,998 shares.

The transactions use code M, indicating derivative exercises rather than open-market buying or selling, and there are no reported sales or tax-withholding dispositions. Footnotes show these awards vest 20% annually from June 28, 2023 and May 16, 2024, consistent with routine director compensation. Without disposals or unusually large changes in position, the investment-sentiment signal is neutral.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Grimm Thomas L

(Last) (First) (Middle)

500 SCOTT STREET

(Street)

WAUSAU WISCONSIN 54403

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Marathon Bancorp, Inc. /MD/ [ MBBC ]

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

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/20/2026

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

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

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

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/20/2026		M		3,599	A	$8.13	21,395	I	By Trust
Common Stock	03/20/2026		M		599	A	$6.48	21,994	I	By Trust
Common Stock								2,998(1)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Options	$8.13	03/20/2026		M			$3,599	06/28/2023	06/28/2032	Common Stock	3,599(2)	$0	2,400(2)	D
Stock Options	$6.48	03/20/2026		M			$599	05/16/2024	05/16/2033	Common Stock	599(3)	$0	900(3)	D

Explanation of Responses:

1. Includes shares of restricted stock which vest at a rate of 20% per year commencing on June 28, 2023.

2. Stock options vest at a rate of 20% per year commencing on June 28, 2023.

3. Stock options vest at a rate of 20% per year commencing on May 16, 2024.

	/s/ Benjamin M. Azoff, pursuant to power of attorney	03/20/2026
	** 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 4 (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.
* Form 4: SEC 1474 (03-26)

FAQ

What did Marathon Bancorp (MBBC) director Thomas L. Grimm do in this Form 4?

Director Thomas L. Grimm exercised stock options to acquire Marathon Bancorp common shares. He converted options into 3,599 and 599 shares at set exercise prices, increasing his indirect holdings through a trust while making no reported share sales.

How many Marathon Bancorp shares did Thomas L. Grimm acquire in the reported transactions?

Grimm acquired 3,599 and 599 shares of Marathon Bancorp common stock through option exercises. These exercises increased his indirect ownership via a trust to 21,994 shares, while his direct holdings stand at 2,998 shares after the reported activity.

At what prices were Thomas L. Grimm’s Marathon Bancorp options exercised?

The options were exercised at fixed prices of $8.13 and $6.48 per share. These are predetermined strike prices from prior equity awards, reflecting compensation structures rather than current market prices for Marathon Bancorp common stock.

Are Thomas L. Grimm’s reported Marathon Bancorp transactions open-market purchases or compensation-related?

They are compensation-related option exercises, not open-market purchases. Form 4 code M and the disclosed exercise prices show Grimm converted existing stock options into common shares as they vested, with no open-market buying or selling involved.

How do vesting terms affect Thomas L. Grimm’s Marathon Bancorp equity awards?

Grimm’s restricted stock and stock options vest at 20% per year starting June 28, 2023 and May 16, 2024. This schedule means additional portions become exercisable over several years, aligning director compensation with longer-term shareholder interests at Marathon Bancorp.