[Form 4] MDU Resources Group, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Jason L. Vollmer, CFO of MDU Resources Group, Inc. (MDU), purchased 5,000 shares of MDU common stock in an open-market transaction on 08/19/2025 at a price of $16.275 per share. Following the purchase, he beneficially owns 339,548.197 shares directly and additionally holds 8,394.3379 shares indirectly through a 401(k) plan held by a trustee. The Form 4 filing was signed by an attorney-in-fact on behalf of Mr. Vollmer and states the transaction was an open-market purchase.

Positive

• Insider open-market purchase of 5,000 shares by the CFO signals a direct acquisition of company stock.
• Clear reporting with both direct and indirect holdings disclosed (339,548.197 direct; 8,394.3379 indirect via 401(k)).

Negative

• None.

Insights

Financial Analyst

TL;DR: CFO bought 5,000 MDU shares at $16.275 on 08/19/2025; small transaction, limited market impact.

The purchase is a routine open-market acquisition by a senior executive, increasing direct ownership to 339,548.197 shares. The size of the trade (5,000 shares) appears modest relative to total holdings and is unlikely to materially affect company valuation or signal a major change in corporate outlook. Documentation is standard for Section 16 reporting and includes an attorney-in-fact signature.

Corporate Governance Expert

TL;DR: Insider disclosure is timely and standard; transaction recorded as open-market purchase and properly reported on Form 4.

The filing identifies Mr. Vollmer as an officer (CFO) and shows both direct and indirect holdings, including a trustee-held 401(k) account. The explanation states the shares were purchased in the open market. There are no amendments, option exercises, or derivative transactions reported, and no indications of atypical arrangements disclosed in this Form 4.

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
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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^*

Vollmer Jason L

(Last) (First) (Middle)

1200 WEST CENTURY AVENUE

(Street)

BISMARCK ND 58503

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MDU RESOURCES GROUP INC [ MDU ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/19/2025

4. 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 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	08/19/2025		P(1)		5,000	A	$16.275	339,548.197	D
Common Stock - 401(k)								8,394.3379	I	By Trustee

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

Explanation of Responses:

1. Mr. Vollmer purchased these shares in an open market transaction.

	Anthony D. Foti, Attorney-in-Fact for Jason L. Vollmer	08/19/2025
	** 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 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.

FAQ

What transaction did Jason L. Vollmer report on the Form 4 for MDU?

He reported an open-market purchase of 5,000 shares of MDU common stock on 08/19/2025 at $16.275 per share.

How many MDU shares does Jason L. Vollmer beneficially own after the reported transaction?

He beneficially owns 339,548.197 shares directly and 8,394.3379 shares indirectly via a 401(k) trustee.

What is Jason L. Vollmer's role at MDU as stated in the filing?

The filing identifies him as an officer with the title CFO.

Was the Form 4 transaction an open-market purchase or part of a plan?

The filing explains the shares were purchased in an open-market transaction.

Who signed the Form 4 filing for Jason L. Vollmer?

Anthony D. Foti signed as Attorney-in-Fact on 08/19/2025 on behalf of Jason L. Vollmer.