Bayou City Energy (NYSE: MNR) adds 9,285 MACH Natural Resources units

Rhea-AI Filing Summary

MACH Natural Resources LP reported that affiliated entity Bayou City Energy Management LLC (BCEM) bought a total of 9,285 common units in open‑market transactions. Purchases occurred over three days at weighted average prices around $13.63 to $14.00 per unit.

After these transactions, 74,835,939 common units are directly held by BCE Mach Aggregator LLC and 23,978 common units by BCEM. BCE Mach Aggregator is indirectly managed by BCEM, and William W. McMullen is BCEM’s Managing Partner; the reporting persons may be deemed to beneficially own these units subject to pecuniary interest.

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

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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^*

McMullen William Wallace

(Last) (First) (Middle)

14201 WIRELESS WAY

SUITE 300

(Street)

OKLAHOMA CITY OKLAHOMA 73134

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
MACH NATURAL RESOURCES LP [ MNR ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/19/2026

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

	Form filed by One Reporting Person
X	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 Units	03/19/2026		P		3,570(1)	A	$14(2)	74,854,202(4)	I	See footnote(4)
Common Units	03/20/2026		P		2,500(1)	A	$14	74,856,702(4)	I	See footnote(4)
Common Units	03/23/2026		P		3,215(1)	A	$13.63(3)	74,859,917(4)	I	See footnote(4)

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^*

McMullen William Wallace

(Last) (First) (Middle)

14201 WIRELESS WAY

SUITE 300

(Street)

OKLAHOMA CITY OKLAHOMA 73134

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

BCE-Mach Aggregator LLC

(Last) (First) (Middle)

C/O BAYOU CITY ENERGY, L.P.

2229 SAN FELIPE STREET, SUITE 1075

(Street)

HOUSTON TEXAS 77019

(City) (State) (Zip)

UNITED STATES

(Country)

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^*

BAYOU CITY ENERGY MANAGEMENT LLC

(Last) (First) (Middle)

C/O BAYOU CITY ENERGY, L.P.

2229 SAN FELIPE STREET, SUITE 1075

(Street)

HOUSTON TEXAS 77019

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. These common units were purchased by Bayou City Energy Management LLC ("BCEM").

2. The price reported in Column 4 is a weighted average price. These common units were purchased by BCEM in multiple transactions at prices ranging from $13.99 to $14.00, inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote (2) to this Form 4.

3. The price reported in Column 4 is a weighted average price. These common units were purchased by BCEM in multiple transactions at prices ranging from $13.535 to $13.65, inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote (3) to this Form 4.

4. After the reported transactions, the reported common units are directly held 74,835,939 by BCE Mach Aggregator LLC ("BCE Aggregator") and 23,978 by BCEM. BCE Aggregator is indirectly managed by BCEM. William W. McMullen is the Managing Partner of BCEM. Accordingly, each of the Reporting Persons may be deemed to beneficially own the securities directly held by BCE Aggregator and BCEM, as applicable, but disclaim beneficial ownership of such common units except to the extent of their respective pecuniary interest therein.

Remarks:

The Reporting Person is a Director of Mach Natural Resources GP LLC, the general partner of the Issuer (the "General Partner"). The Issuer is managed by the directors and executive officers of the General Partner.

	William W. McMullen, By: /s/ William W. McMullen	03/23/2026
	BCE-Mach Aggregator LLC, By: /s/ William W. McMullen, Name: William W. McMullen, Title: Authorized Signatory	03/23/2026
	Bayou City Energy Management LLC, By: /s/ William W. McMullen, Name: William W. McMullen, Title: Managing Partner	03/23/2026
	** 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 insider activity did MACH Natural Resources LP (MNR) report in this Form 4?

The filing shows affiliated entity Bayou City Energy Management LLC buying 9,285 common units in three open‑market transactions. These purchases occurred on March 19, 20, and 23, 2026, at weighted average prices between $13.535 and $14.00 per unit.

Who actually purchased the MACH Natural Resources (MNR) common units?

Bayou City Energy Management LLC executed the purchases, not an individual. Footnotes explain that BCEM bought the units and that reporting persons, including William W. McMullen, may be deemed beneficial owners only to the extent of their pecuniary interest in those securities.

How many MACH Natural Resources (MNR) units are held after these transactions?

After the reported buys, 74,835,939 common units are directly held by BCE Mach Aggregator LLC and 23,978 common units by Bayou City Energy Management LLC. Together, these related entities hold 74,859,917 common units following the March 2026 open‑market purchases disclosed.

At what prices were the MACH Natural Resources (MNR) units purchased?

The reported prices are weighted averages. One set of transactions ranged from $13.99 to $14.00 per unit, and another from $13.535 to $13.65 per unit. The Form 4 notes the filer can provide exact trade breakdowns upon request.

What is William W. McMullen’s relationship to these MACH Natural Resources (MNR) holdings?

William W. McMullen is a reporting person and the Managing Partner of Bayou City Energy Management LLC. The filing states that each reporting person may be deemed to beneficially own units held by BCE Mach Aggregator and BCEM but disclaims ownership beyond their pecuniary interests.

Are these MACH Natural Resources (MNR) transactions direct or indirect holdings?

The Form 4 classifies the transactions as indirect. The common units are directly held by BCE Mach Aggregator LLC and Bayou City Energy Management LLC, with the reporting persons’ interests arising through their relationships with these entities rather than through direct personal ownership.