GLENCORE INTERNATIONAL AG - 30 Sep 2025 Form 4 Insider Report for CENTURY ALUMINUM CO (CENX)

Role: 10%+ Owner
Signature: GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Director By: /s/ Steven Kalmin Name: Steven Kalmin Title: Director
Issuer symbol: CENX
Transactions as of: 30 Sep 2025
Net transactions value: $0
Form type: 4
Filing time: 02 Oct 2025, 06:00:26 UTC
Previous filing: 02 Jul 2025
Next filing: 13 Nov 2025
SEC: View on sec.gov

Reporting Owners (3)

Name	Relationship	Address	Signature	Signature date	CIK
GLENCORE INTERNATIONAL AG	10%+ Owner	BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND	GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Director By: /s/ Steven Kalmin Name: Steven Kalmin Title: Director	02 Oct 2025	0001032383
Glencore AG	10%+ Owner	BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND	GLENCORE AG By: /s/ Martin Haering Name: Martin Haering Title: Director By: /s/ Carlos Perezagua Name: Carlos Perezagua Title: Director	02 Oct 2025	0001449539
Glencore plc	10%+ Owner	BAARERMATTSTRASSE 3, P.O. BOX 1363, BAAR, SWITZERLAND	GLENCORE PLC By: /s/ John Burton Name: John Burton Title: Company Secretary	02 Oct 2025	0001521365

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CENX	Common Stock	Conversion of derivative security		+2,848	+0.02%		12,557,356	30 Sep 2025	See Footnote	F1, F2, F3
holding	CENX	Common Stock						27,500,000	30 Sep 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CENX	Series A Convertible Preferred Stock	Conversion of derivative security		-28	-0.06%		49,486	30 Sep 2025	Common Stock	2,848		See Footnote	F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents shares of Common Stock acquired upon conversion of 28.48 shares of Series A Convertible Preferred Stock on September 30, 2025.
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 has no expiration date.
F3	The shares of Common Stock reported in Line 1 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 2 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.