[Form 4] First Interstate BancSystem, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Insider sale disclosed: This Form 4 shows John M. Heyneman Jr. and affiliated reporting persons sold 11,818 shares of First Interstate BancSystem, Inc. (FIBK) on 08/14/2025 at a weighted average price of $30.185 per share, with prices in the range $30.07 to $30.23.

The filing reports 5,224 shares owned directly by the reporting person after the sale and a total of 1,414,636 shares beneficially owned indirectly by affiliated trusts and entities. The filing explains the indirect group ownership arrangement and identifies record holders by entity, with allocation details in the footnotes.

Positive

• Transparent disclosure of weighted-average sale price and price range for the transactions
• Detailed explanation of group and indirect beneficial ownership across trusts and partnerships
• Proper signatures and attorney-in-fact attestations indicating procedural compliance

Negative

• Insider sale of 11,818 shares on 08/14/2025, which reduces the reporting person’s direct holdings
• Concentrated indirect ownership (1,414,636 shares) may merit investor attention for governance and control considerations

Insights

Corporate Governance Expert

TL;DR: Routine insider sale with clear group ownership disclosures; filing meets Section 16 transparency requirements.

The Form 4 documents a reported sale of 11,818 common shares by John M. Heyneman Jr. at an indicated weighted average price of $30.185. The filing includes detailed footnotes explaining aggregated beneficial ownership across trusts and partnerships and disclaims beneficial ownership beyond pecuniary interest. Signatures and attorney-in-fact attestations are present, supporting procedural compliance. From a governance perspective this is a standard disclosure: it clarifies ownership structure and confirms the reporting persons intend to coordinate future filings from a common perspective.

Securities/Equity Analyst

TL;DR: Small proportionate sale relative to total reported beneficial holdings; limited immediate market impact.

The sale of 11,818 shares at ~$30.19 each represents a modest liquidity event versus the reported indirect beneficial ownership of 1,414,636 shares. The residual direct ownership of 5,224 shares is small. Because the filing discloses a large indirect stake held via trusts and a partnership, the single reported sale appears marginal in scale and unlikely to materially alter control or valuation. The report’s price range disclosure adds useful granularity for analysts reconstructing realized proceeds.

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^*

HEYNEMAN JOHN M JR

(Last) (First) (Middle)

P.O. BOX 30918

(Street)

BILLINGS MT 59116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
FIRST INTERSTATE BANCSYSTEM INC [ FIBK ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/14/2025

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

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

	Form filed by One Reporting Person
X	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	08/14/2025		S		11,818	D	$30.185(1)	5,224	D
Common Stock								1,414,636	I	see footnote(2)(3)

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

1. Name and Address of Reporting Person^*

HEYNEMAN JOHN M JR

(Last) (First) (Middle)

P.O. BOX 30918

(Street)

BILLINGS MT 59116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

John M Heyneman Jr. Trust

(Last) (First) (Middle)

P.O. BOX 7113

(Street)

BILLINGS MT 59103

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Rae Ann Morss & John Heyneman Jr., Trustees FBO Rae Ann Morss Exemption Trust Under the Scott Family 1996 Trust

(Last) (First) (Middle)

P.O. BOX 7113

(Street)

BILLINGS MT 59103

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Riki Rae Scott Davidson & John Heyneman Jr., Trustees FBO Riki Scott Davidson Exemption Trust Under the Scott Family 1996 Trust

(Last) (First) (Middle)

P.O. BOX 7113

(Street)

BILLINGS MT 59103

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Towanda Investments Limited Partnership

(Last) (First) (Middle)

P.O. BOX 7113

(Street)

BILLINGS MT 59103

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.07 to $30.23. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holder of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon request, the full information regarding the number of shares sold at each separate price within the ranges set forth above.

2. As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4 and 5, if any, together with John Heyneman, Jr. with the indication of direct or indirect ownership in Table I being made from John Heyneman, Jr.'s perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

3. Composed of 150,000 shares held of record by John M Heyneman Jr. Trust, 85,836 shares held of record by Riki Rae Scott Davidson & John Heyneman Jr., Trustees FBO Riki Scott Davidson Exemption Trust Under the Scott Family 1996 Trust, 85,836 shares held of record by Rae Ann Morss & John Heyneman Jr., Trustees FBO Rae Ann Morss Exemption Trust Under the Scott Family 1996 Trust, 1,085,792 shares held of record by Towanda Investments Limited Partnership, 4,552 shares held of record by John Heyneman, Jr.'s spouse, 1095 shares held of record by John Heyneman, Jr.'s daughter, 1,215 shares held of record by John Heyneman, Jr.'s son Quinn, and 310 shares held of record by John Heyneman, Jr.'s son Bae-John.

Remarks:

	/s/ Kirk D. Jensen, Attorney-in-Fact for Reporting Person	08/18/2025
	RIKI RAE SCOTT DAVIDSON & JOHN HEYNEMAN JR., TRUSTEES FBO RIKI SCOTT DAVIDSON EXEMPTION TRUST UNDER THE SCOTT FAMILY 1996 TRUST, By:**	08/18/2025
	RAE ANN MORSS & JOHN HEYNEMAN JR., TRUSTEES FBO RAE ANN MORSS EXEMPTION TRUST UNDER THE SCOTT FAMILY 1996 TRUST, By:**	08/18/2025
	TOWANDA INVESTMENTS LIMITED PARTNERSHIP, By:**	08/18/2025
	JOHN M HEYNEMAN JR. TRUST, By**	08/18/2025
	**By: /s/ Timothy Leuthold, Attorney-in-Fact for Reporting Person	08/18/2025
	** 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 the Form 4 report for FIBK?

The Form 4 reports a sale of 11,818 shares of First Interstate BancSystem, Inc. on 08/14/2025 at a weighted average price of $30.185 per share.

How many First Interstate (FIBK) shares does the reporting person beneficially own after the sale?

The filing reports 5,224 shares owned directly after the reported transaction and 1,414,636 shares beneficially owned indirectly by affiliated trusts and entities.

What price range was disclosed for the FIBK sale?

The footnote states the sale prices ranged from $30.07 to $30.23, and the reported price is a weighted average of $30.185.

Who are the reporting persons listed on the Form 4 for FIBK?

Reporting persons include John M. Heyneman Jr., the John M Heyneman Jr. Trust, two trustee-managed exemption trusts, and Towanda Investments Limited Partnership, all identified as directors and 10% owners.

Does the filing explain the nature of indirect ownership?

Yes. Footnotes describe agreements among reporting persons and other stockholders that may create a deemed group, and they specify record holdings by each trust, partnership, and family member.