Black Stone Minerals insider increases stake to 3.50M units via open‑market buys

Rhea-AI Filing Summary

Insider purchases increased both direct and indirect stakes in Black Stone Minerals (BSM). Thomas L. Carter Jr., who serves as CEO, President and Chairman and is also a director, reported three open‑market purchases executed on 09/08/2025, 09/09/2025 and 09/10/2025 totaling 25,370 common units at weighted average prices in ranges of $11.88–$11.91, $12.04–$12.10 and $12.22–$12.38, respectively. Following the reported transactions the filing shows 3,497,401 common units beneficially owned directly by the reporting person. The Form 4 also discloses significant indirect holdings through trusts and entities, including 11,481,503 units held by Carter2221, Ltd., and multiple 1995 trusts and spouse holdings. The filing is a routine Section 16 disclosure of insider purchases and beneficial ownership.

Positive

• Insider purchases totaling 25,370 common units, showing additional direct accumulation
• Direct beneficial ownership increased to 3,497,401 units following reported transactions
• Complete disclosure of indirect holdings via trusts and entities, including 11,481,503 units held by Carter2221, Ltd.

Negative

• Concentrated indirect ownership through multiple trusts and an entity may indicate significant control by related parties
• No information on the dollar value of total holdings beyond per‑transaction weighted price ranges for the reported purchases

Insights

Financial Analyst

TL;DR: Insider purchases of 25,370 units modestly increased direct ownership; material indirect stakes remain substantial.

The filing documents three open‑market purchases totaling 25,370 common units at weighted price ranges between $11.88 and $12.38. Direct beneficial ownership reported after the transactions is 3,497,401 units. From a capital‑markets perspective, these purchases represent continued insider accumulation but are small relative to the large indirect holdings disclosed (for example, 11,481,503 units held by Carter2221, Ltd.). This pattern increases the reporting person’s direct stake modestly while overall family/related‑party control remains highly concentrated via trusts and entities. No derivative transactions were reported.

Corporate Governance Expert

TL;DR: Disclosure is complete and timely; shows concentrated ownership via related trusts and entities.

The Form 4 is properly executed by an attorney‑in‑fact and discloses the reporting person’s roles (CEO, President, Chairman, Director) and both direct and multiple indirect holdings through named trusts and an entity. The filing notes weighted average price ranges and provides the issuer and transaction dates. From a governance standpoint, the record highlights concentrated insider and family ownership, which is relevant for control considerations and shareholder voting dynamics. The filing contains no amendments or derivative activity.

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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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^*

Carter Thomas L Jr

(Last) (First) (Middle)

1001 FANNIN STREET, SUITE 2020

(Street)

HOUSTON TX 77002

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Black Stone Minerals, L.P. [ BSM ]

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

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO, President, and Chairman

3. Date of Earliest Transaction (Month/Day/Year)
09/08/2025

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 units representing limited partner interests	09/08/2025		P		13,527	A	$11.8975(1)	3,485,558	D
Common units representing limited partner interests	09/09/2025		P		1,307	A	$12.0655(2)	3,486,865	D
Common units representing limited partner interests	09/10/2025		P		10,536	A	$12.3191(3)	3,497,401	D
Common units representing limited partner interests								13,141	I	By Fowler Thomas Carter 1995 Trust
Common units representing limited partner interests								37,741	I	By Georgia Elizabeth Carter 1995 Trust
Common units representing limited partner interests								167,155	I	By spouse
Common units representing limited partner interests								37,742	I	By Molly Leachman Carter 1995 Trust
Common units representing limited partner interests								37,741	I	By Katherine Ross Carter 1995 Trust
Common units representing limited partner interests								11,481,503	I	By Carter2221, Ltd.

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. The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions at prices ranging from $11.88 to $11.91, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote.

2. The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions at prices ranging from $12.04 to $12.10, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote.

3. The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions at prices ranging from $12.22 to $12.38, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote.

Remarks:

	/s/ Steve Putman, attorney-in-fact for Thomas L. Carter, Jr.	09/10/2025
	** 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 transactions did Thomas L. Carter Jr. report on the Form 4 for BSM?

He reported three open‑market purchases on 09/08/2025, 09/09/2025, and 09/10/2025 totaling 25,370 common units at weighted average price ranges between $11.88 and $12.38.

How many common units does the reporting person beneficially own directly after these transactions?

The Form 4 shows 3,497,401 common units beneficially owned directly following the reported transactions.

Does the filing disclose indirect holdings for Thomas L. Carter Jr.?

Yes. The filing discloses multiple indirect holdings, including trusts and entities such as Carter2221, Ltd. with 11,481,503 units and several 1995 trusts and spouse holdings with disclosed unit counts.

Were any derivative securities reported on this Form 4?

No. Table II for derivative securities contains no reported transactions or holdings.

Who signed the Form 4 and when?

The Form 4 was signed by /s/ Steve Putman, attorney‑in‑fact for Thomas L. Carter, Jr. on 09/10/2025.