First Interstate BancSystem directors, 10% owners report stock sale

Rhea-AI Filing Summary

First Interstate BancSystem Inc. (FIBK) insiders reported a sale of company stock by a group of related reporting persons who are directors and 10% owners. On 11/21/2025, they sold 30,432 shares of common stock at a price of $31.03 per share.

After this transaction, they report indirect beneficial ownership of 1,414,636 shares of common stock, as detailed in the footnotes describing various trusts, family members, and an investment partnership. Additional positions include 47,482 shares held indirectly by Awe' LLC, 5,224 shares held directly, and 30,154 shares held indirectly by Bench Ranch LLC.

The filing notes that, due to certain agreements with other stockholders, the reporting persons may be deemed part of a group and may be deemed to share beneficial ownership of the reported securities, although each disclaims beneficial ownership beyond its pecuniary interest.

Insider Trade Summary

Net Seller: 30,432 shares ($944,305)

Net Sell 4 txns

Insider HEYNEMAN JOHN M JR, John M Heyneman Jr. Trust, Rae Ann Morss & John Heyneman Jr., Trustees FBO Rae Ann Morss Exemption Trust Under the Scott Family 1996 Trust, Riki Rae Scott Davidson & John Heyneman Jr., Trustees FBO Riki Scott Davidson Exemption Trust Under the Scott Family 1996 Trust, Towanda Investments Limited Partnership

Role Director, 10% Owner | 10% Owner | 10% Owner | 10% Owner | 10% Owner

Sold 30,432 shs ($944K)

Type	Security	Shares	Price	Value
Sale	Common Stock	30,432	$31.03	$944K
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 1,414,636 shares (Indirect, see footnote); Common Stock — 5,224 shares (Direct)

Footnotes (1)

1. 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. 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.

Form 4 Insider Transactions: What Each Field Means →

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^*

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)
11/21/2025

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	11/21/2025		S		30,432	D	$31.03	1,414,636	I	see footnote(1)(2)
Common Stock								47,482	I	By Awe' LLC
Common Stock								5,224	D
Common Stock								30,154	I	By Bench Ranch LLC

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. 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.

2. 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	11/25/2025
	JOHN M HEYNEMAN JR. TRUST, By**	11/25/2025
	RAE ANN MORSS & JOHN HEYNEMAN JR., TRUSTEES FBO RAE ANN MORSS EXEMPTION TRUST UNDER THE SCOTT FAMILY 1996 TRUST, By:**	11/25/2025
	RIKI RAE SCOTT DAVIDSON & JOHN HEYNEMAN JR., TRUSTEES FBO RIKI SCOTT DAVIDSON EXEMPTION TRUST UNDER THE SCOTT FAMILY 1996 TRUST, By:**	11/25/2025
	TOWANDA INVESTMENTS LIMITED PARTNERSHIP, By:**	11/25/2025
	**By: /s/ Timothy Leuthold, Attorney-in-Fact for Reporting Person	11/25/2025
	** 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 insider transaction did FIBK report on this Form 4?

The filing reports that a group of related insiders of First Interstate BancSystem Inc. (FIBK), who are directors and 10% owners, sold 30,432 shares of common stock on 11/21/2025 at $31.03 per share.

How many FIBK shares do the reporting persons beneficially own after the sale?

Following the reported sale, the group reports indirect beneficial ownership of 1,414,636 shares of FIBK common stock, plus separate positions of 47,482 shares indirectly by Awe' LLC, 5,224 shares held directly, and 30,154 shares indirectly by Bench Ranch LLC.

What is the relationship of the reporting persons to FIBK?

The reporting persons are identified as both Directors and 10% Owners of First Interstate BancSystem Inc. (FIBK), reflecting significant roles and ownership stakes.

How is the 1,414,636-share FIBK position held?

The 1,414,636 shares of FIBK common stock are held indirectly through various vehicles, including the John M Heyneman Jr. Trust, exemption trusts under the Scott Family 1996 Trust, Towanda Investments Limited Partnership, and accounts for certain family members, as described in the footnotes.

Do the reporting persons claim full beneficial ownership of all reported FIBK shares?

The filing states that, because of certain agreements with other stockholders, the reporting persons may be deemed part of a group, but each disclaims beneficial ownership of any such securities except to the extent of its pecuniary interest.

Was this FIBK Form 4 filed by one or multiple reporting persons?

The Form 4 was indicated as filed by more than one reporting person, reflecting multiple related trusts and entities reporting their holdings together.