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

Rhea-AI Filing Summary

MP Materials Chief Accounting Officer David Gregory Infuso reported a routine tax-related share disposition. On April 1, 2026, 804 shares of common stock were withheld at $48.41 per share to satisfy tax obligations on vested restricted stock units. Following this withholding, he directly owns 48,442 shares of MP Materials common stock. This was not an open-market sale but an automatic share withholding for taxes tied to equity compensation.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Infuso David Gregory

Role Chief Accounting Officer

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	804	$48.41	$39K

Holdings After Transaction: Common Stock — 48,442 shares (Direct)

Footnotes (1)

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Key Figures

Tax-withheld shares: 804 shares Per-share value: $48.41 per share Shares held after: 48,442 shares +1 more

4 metrics

Tax-withheld shares 804 shares Common stock withheld for taxes on RSU vesting April 1, 2026

Per-share value $48.41 per share Value used for the 804-share tax-withholding disposition

Shares held after 48,442 shares Direct MP Materials common stock ownership after withholding

Transaction date April 1, 2026 Date RSUs vested and shares were withheld for taxes

Key Terms

restricted stock units, tax withholding obligations, Chief Accounting Officer

3 terms

restricted stock units financial

"restricted stock units that vested on April 1, 2026"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

tax withholding obligations financial

"shares withheld to satisfy tax withholding obligations applicable to the vesting"

Chief Accounting Officer financial

"Infuso David Gregory, Chief Accounting Officer"

A chief accounting officer is a senior executive responsible for overseeing a company's financial records and ensuring all accounting practices are accurate and compliant with regulations. They play a key role in preparing financial reports that help investors understand the company's financial health, much like a trusted navigator guiding a ship through complex waters. Their work ensures transparency and trust in the company's financial information.

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^*

Infuso David Gregory

(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 Accounting Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/01/2026

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	04/01/2026		F		804(1)	D	$48.41	48,442	D

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. Represents shares withheld to satisfy tax withholding obligations applicable to the vesting of restricted stock units that vested on April 1, 2026.

Remarks:

	/s/ Elliot D. Hoops, attorney-in-fact for David Gregory Infuso	04/01/2026
	** 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 transaction did MP’s David Gregory Infuso report on this Form 4?

David Gregory Infuso reported a tax-related share disposition. On April 1, 2026, 804 MP Materials common shares were withheld to cover taxes on vested restricted stock units, rather than sold in the open market, as part of routine equity compensation administration.

How many MP (MP) shares were withheld for taxes in this filing?

The filing shows 804 MP Materials common shares were withheld. These shares covered tax withholding obligations arising from restricted stock units that vested on April 1, 2026, and reflect a mechanistic compensation event rather than a discretionary open-market share sale by the executive.

At what price were the withheld MP (MP) shares valued in the Form 4?

The 804 withheld shares were valued at $48.41 per share. This price is used solely for reporting the tax-withholding disposition and does not represent a separate open-market trade, but rather the value applied to shares withheld to satisfy tax obligations on vested stock units.

How many MP (MP) shares does David Gregory Infuso hold after this transaction?

After the tax withholding, David Gregory Infuso directly holds 48,442 MP Materials common shares. This remaining position, reported in the Form 4, shows his continuing ownership stake following the routine share withholding tied to the vesting of restricted stock units on April 1, 2026.

Was the MP (MP) Form 4 transaction an open-market sale by the executive?

No, the transaction was not an open-market sale. The Form 4 describes shares withheld to satisfy tax obligations from restricted stock units vesting on April 1, 2026, meaning the company retained 804 shares rather than the executive choosing to sell them on the market.