[Form 4] MP Materials Corp. / DE Insider Trading Activity

Rhea-AI Filing Summary

MP Materials Corp. Chief Operating Officer Michael Stuart Rosenthal reported an open-market purchase of 17,000 shares of common stock on May 20, 2026 at 56.62 per share. After this transaction, he directly holds 1,333,673 shares and has an additional 126,622 shares held indirectly through the Rosenthal Family Trust.

Insights

Equity analyst

COO makes a modest open-market share purchase, expanding an already large stake.

MP Materials Corp. Chief Operating Officer Michael Stuart Rosenthal executed an open-market purchase of 17,000 common shares at 56.62 per share. Open-market buys typically reflect an executive’s willingness to increase personal exposure at current prices.

Following the trade, Rosenthal’s direct holdings total 1,333,673 shares, alongside 126,622 shares held indirectly via the Rosenthal Family Trust. The purchased amount is small relative to his overall position, suggesting a routine increase rather than a transformative move.

There are no derivative positions disclosed in this filing, so the picture here is purely common-stock ownership. Future company filings may provide additional context if his ownership changes significantly from these levels.

Insider Trade Summary

Net Buyer: 17,000 shares ($962,540)

Net Buy 2 txns

Insider Rosenthal Michael Stuart

Role Chief Operating Officer

Bought 17,000 shs ($963K)

Type	Security	Shares	Price	Value
Purchase	Common Stock	17,000	$56.62	$963K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 1,333,673 shares (Direct, null); Common Stock — 126,622 shares (Indirect, By Rosenthal Family Trust)

Footnotes (1)

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^*

Rosenthal Michael Stuart

(Last) (First) (Middle)

1700 S. PAVILION CENTER DRIVE, SUITE 800

(Street)

LAS VEGAS NEVADA 89135

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026

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

X	Form filed by One Reporting Person
	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 Stock	05/20/2026		P		17,000	A	$56.62	1,333,673	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:

Remarks:

	/s/ Elliot D. Hoops, Attorney-In-Fact for Michael Rosenthal	05/20/2026
	** 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)