GLENCORE INTERNATIONAL AG - 10 Nov 2025 Form 4 Insider Report for CENTURY ALUMINUM CO (CENX)

Reporting relationship: 10%+ Owner
Issuer ticker: CENX
Reported as of: 10 Nov 2025
Net transaction value: -$272,250,000
SEC form: 4
Accepted by SEC: 13 Nov 2025, 17:59:31 UTC
Prior SEC filing: 02 Oct 2025
Next SEC filing: 04 Mar 2026
Source filing: View source filing
Reporting owner signature: GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Attorney-in-Fact

Key filing fact

GLENCORE INTERNATIONAL AG filed Form 4 for CENTURY ALUMINUM CO (CENX) on 13 Nov 2025.

Key facts

This page summarizes GLENCORE INTERNATIONAL AG's Form 4 filing for CENTURY ALUMINUM CO (CENX).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 13 Nov 2025, 17:59.

Change

Previous filing in this sequence was filed on 02 Oct 2025.
Current net transaction value: -$272,250,000.

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 (3)

CIK 0001032383 Primary reporting owner

GLENCORE INTERNATIONAL AG

Relationship: 10%+ Owner
Address: BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND
Signature: GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Attorney-in-Fact
Signature date: 13 Nov 2025

CIK 0001449539

Glencore AG

Relationship: 10%+ Owner
Address: BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND
Signature: GLENCORE AG By: /s/ John Burton Name: John Burton Title: Attorney-in-Fact
Signature date: 13 Nov 2025

CIK 0001521365

Glencore plc

Relationship: 10%+ Owner
Address: BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND
Signature: GLENCORE PLC By: /s/ John Burton Name: John Burton Title: Company Secretary
Signature date: 13 Nov 2025

Reported non-derivative transactions

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

CENX transaction

Common Stock

Sale

Transaction value: $272,250,000
Shares: -9,000,000
Change %: -33%
Price: $30.25
Shares after: 18,500,000
Date: 10 Nov 2025
Ownership: Direct

CENX transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +4,948,591
Change %: +39%
Price
Shares after: 17,505,947
Date: 10 Nov 2025
Ownership: See Footnote
Footnotes: F1, F2, F3

Reported derivative securities

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

CENX transaction Derivative

Series A Convertible Preferred Stock

Conversion of derivative security

Transaction value
Shares: -49,486
Change %: -100%
Price
Shares after: 0
Date: 10 Nov 2025
Ownership: See Footnote
Underlying class: Common Stock
Underlying amount: 4,948,591
Exercise price
Footnotes: F1, F2, F3

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

Represents shares of Common Stock acquired upon the automatic conversion of 49,485.91 shares of Series A Convertible Preferred Stock upon the consummation of the transaction reported in Line 1 of Table 1.

Footnote F2

Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock was acquired on July 8, 2008 and has no expiration date.

Footnote F3

The shares of Common Stock reported in Line 2 of Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and may be deemed to be indirectly beneficially owned by Glencore International AG. The Common Stock reported on Line 1 of Table I is held directly by Glencore International AG. Glencore International AG is wholly-owned by Glencore plc, which may be deemed an indirect beneficial owner of the securities held by Glencore AG and Glencore International AG.

SEC remarks

Exhibit List: Exhibit 24.1 and Exhibit 24.2.