Barbara Humpton - 01 Oct 2026 Form 4 Insider Report for USA Rare Earth, Inc. (USAR)

Reporting relationship: Former Chief Executive Officer, Former Director
Issuer ticker: USAR
Reported as of: 01 Oct 2026
Net transaction value: -$1,215,376
SEC form: 4
Accepted by SEC: 05 Oct 2026, 20:48:29 UTC
Prior SEC filing: 13 Feb 2026
Source filing: View source filing
Reporting owner signature: /s/ Derek Ching, attorney-in-fact for Barbara Humpton

Key filing fact

Barbara Humpton filed Form 4 for USA Rare Earth, Inc. (USAR) on 05 Oct 2026.

Key facts

This page summarizes Barbara Humpton's Form 4 filing for USA Rare Earth, Inc. (USAR).
7 reported transactions and 3 derivative rows are listed below.
Accepted by SEC: 05 Oct 2026, 20:48.

Change

Previous filing in this sequence was filed on 13 Feb 2026.
Current net transaction value: -$1,215,376.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001790041 Primary reporting owner

Humpton Barbara

Relationship: Former Chief Executive Officer, Former Director
Address: 100 W. AIRPORT BLVD., STILLWATER
Signature: /s/ Derek Ching, attorney-in-fact for Barbara Humpton
Signature date: 05 Oct 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

USAR transaction

Common Stock, par value $0.0001 per share

Options Exercise

Transaction value
Shares: +83,554
Change %
Price: $13.80^*
Shares after: 83,554
Date: 01 Oct 2026
Ownership: Direct

USAR transaction

Common Stock, par value $0.0001 per share

Options Exercise

Transaction value
Shares: +104,443
Change %: +125%
Price: $13.80^*
Shares after: 187,997
Date: 01 Oct 2026
Ownership: Direct

USAR transaction

Common Stock, par value $0.0001 per share

Options Exercise

Transaction value
Shares: +31,333
Change %: +17%
Price: $13.80^*
Shares after: 219,330
Date: 01 Oct 2026
Ownership: Direct

USAR transaction

Common Stock, par value $0.0001 per share

Sale

Transaction value: $1,215,376
Shares: -88,391
Change %: -40%
Price: $13.75
Shares after: 130,939
Date: 02 Oct 2026
Ownership: Direct
Footnotes: F1, F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

USAR transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -83,554
Change %: -33%
Price: $0.000000^*
Shares after: 167,108
Date: 01 Oct 2026
Ownership: Direct
Underlying class: Common Stock, par value $0.0001 per share
Underlying amount: 83,554
Exercise price
Footnotes: F3, F4

USAR transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -104,443
Change %: -33%
Price: $0.000000^*
Shares after: 208,884
Date: 01 Oct 2026
Ownership: Direct
Underlying class: Common Stock, par value $0.0001 per share
Underlying amount: 104,443
Exercise price
Footnotes: F3, F4

USAR transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -31,333
Change %: -50%
Price: $0.000000^*
Shares after: 31,333
Date: 01 Oct 2026
Ownership: Direct
Underlying class: Common Stock, par value $0.0001 per share
Underlying amount: 31,333
Exercise price
Footnotes: F4, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Section 16 status

Barbara Humpton is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may still apply in specific circumstances.

Explanation of responses 5 footnotes

Footnote F1

Sell-to-cover for taxes associated with the vesting of RSUs received by the reporting person.

Footnote F2

This figure is the weighted average sales price of multiple trades ranging from $13.665 to $14.00 per share. The reporting person undertakes to provide the SEC Staff, USA Rare Earth, Inc. or a shareholder of USA Rare Earth, Inc. full information about the number of shares sold at each separate price upon request.

Footnote F3

The restricted stock units ("RSUs") were granted on October 1, 2025. Pursuant to the reporting person's retirement agreement with the issuer, one-third vested on October 1, 2026 and the remainder is forfeited.

Footnote F4

Each restricted stock unit represents the right to receive, at settlement, one (1) share of the Issuer's common stock.

Footnote F5

The RSUs were granted on October 1, 2025. Pursuant to the reporting person's retirement agreement with the issuer, one-half vested on October 1, 2026 and the remainder is forfeited.

SEC remarks

Exhibit 24