[Form 4] MP Materials Corp. Insider Trading Activity

Rhea-AI Filing Summary

Michael Stuart Rosenthal, Chief Operating Officer of MP Materials Corp. (MP), reported multiple open-market sales totaling 150,000 shares on 08/29/2025. The sales were executed in multiple transactions at weighted-average prices reported as $71.48, $72.56 and $73.23, with per-tranche price ranges disclosed in the filing. Following the transactions, the filing shows 1,284,409 shares held directly and 126,622 shares held indirectly through the Rosenthal Family Trust.

Insights

Securities Analyst

TL;DR: COO sold 150,000 MP shares across multiple trades; remaining direct and trust holdings remain substantial.

These Form 4 disclosures reflect routine open-market dispositions rather than option exercises or derivative activity. The total reported disposed amount is 150,000 common shares, sold at weighted-average prices across three reported price bands. Post-transaction direct ownership is shown as 1,284,409 shares, with an additional 126,622 held indirectly via a family trust. From an investor-monitoring perspective, concentrated insider sales can be noteworthy, but this filing does not by itself indicate governance change or derivative-based dilution. The filing includes standard weighted-average price footnotes and offers to provide per-trade breakouts on request.

Corporate Governance Expert

TL;DR: Disclosure is complete for open-market sales; no indication of plan-based transactions was checked.

The Form 4 indicates the reporting person checked the box for a single reporting person filing and listed officer title as Chief Operating Officer. There is no indication the sales were made pursuant to a Rule 10b5-1 plan in the visible checkboxes. The filing provides the required explanatory footnotes about weighted-average prices and offers to supply detailed per-trade data to the company or SEC staff, which aligns with compliance norms for clarity in insider disposition reporting.

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

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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^*

Rosenthal Michael Stuart

(Last) (First) (Middle)

1700 S. PAVILION CENTER DRIVE, SUITE 800

(Street)

LAS VEGAS NV 89135

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MP Materials Corp. / DE [ MP ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/29/2025

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	08/29/2025		S		83,874	D	$71.48(1)	1,350,535	D
Common Stock	08/29/2025		S		52,063	D	$72.56(2)	1,298,472	D
Common Stock	08/29/2025		S		14,063	D	$73.23(3)	1,284,409	D
Common Stock								126,622	I	By Rosenthal Family Trust

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 shares were sold in multiple transactions at prices ranging from $71.07 to $72.06. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $72.07 to $73.06. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $73.07 to $73.46. The reporting person undertakes to provide to MP Materials Corp., any security holder of MP Materials Corp., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) to this Form 4.

Remarks:

	/s/ Elliot D. Hoops, Attorney-In-Fact for Michael Rosenthal	08/29/2025
	** 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

How many MP (MP) shares did Michael Rosenthal sell on 08/29/2025?

The filing reports 150,000 shares sold on 08/29/2025 across multiple transactions.

At what prices were the MP shares sold by the COO?

Sales were reported at weighted-average prices of $71.48, $72.56, and $73.23 with disclosed per-trade ranges for each tranche.

What were Michael Rosenthal's MP holdings after the reported sales?

After the transactions the filing shows 1,284,409 shares held directly and 126,622 shares held indirectly through the Rosenthal Family Trust.

Was the sale reported as pursuant to a 10b5-1 plan?

In the provided content, the checkbox indicating a 10b5-1 plan was not shown as checked for these transactions.

Who signed the Form 4 on behalf of Michael Rosenthal?

The Form 4 signature line shows Elliot D. Hoops, Attorney-In-Fact signing for Michael Rosenthal on 08/29/2025.