[Form 4] Century Aluminum Co Insider Trading Activity

Rhea-AI Filing Summary

Form 4 filing for Century Aluminum Co. (CENX) dated 07/02/2025 discloses a single reportable transaction by the Glencore group, which is a >10% beneficial owner of the issuer.

• Transaction date: 06/30/2025
• Security: Series A Convertible Preferred Stock converted into common stock.
• Amount converted: 164.77 preferred shares, automatically exchangeable on a 1-for-100 basis into 16,477 CENX common shares.
• Resulting ownership: Glencore reports 12,554,508 common shares held indirectly through its subsidiary Glencore AG after the conversion.
• A separate line in Table I references 27,500,000 common shares marked as “D” (disposed), but no execution date or price is provided in the filing excerpt; therefore the timing and nature of that figure cannot be confirmed from the supplied text.

The filing clarifies that Glencore AG directly owns the converted securities, while Glencore International AG and Glencore plc are indirect beneficial owners. No sale proceeds, option exercises, or additional derivative activity are reported.

Materiality assessment: The conversion adds a de minimis 16.5 k shares to Glencore’s existing 12.55 m-share position, implying an immaterial percentage change in its ownership stake. Without details on the 27.5 m-share “D” line, the net ownership change appears modest and the filing is judged informational rather than market-moving.

Insights

Equity Analyst

TL;DR – Minor preferred-to-common conversion; no meaningful change in Glencore’s ~10% stake, so limited market impact.

Form 4 shows Glencore converting 164.77 Series A preferred shares into 16,477 common shares on 06/30/25. Post-conversion beneficial ownership stands at 12.55 m shares. With Century Aluminum’s public float roughly 92 m shares (FY-24 10-K), the incremental shares move Glencore’s stake by less than 0.02 ppt. The filing carries no sale price, option exercise, or cash proceeds and does not alter control dynamics. An unexplained 27.5 m-share “D” line lacks execution detail and therefore cannot be interpreted as a live sale. Overall, the disclosure is routine housekeeping required under Section 16(a) and should not influence valuation, liquidity, or governance expectations.

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
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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^*

GLENCORE INTERNATIONAL AG

(Last) (First) (Middle)

BAARERMATTSTRASSE 3

P.O. BOX 1363

(Street)

BAAR V8 CH-6341

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CENTURY ALUMINUM CO [ CENX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
06/30/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

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

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

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	06/30/2025		C		16,477	A	(1)(2)	12,554,508	I	See Footnote(3)
Common Stock								27,500,000	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
Series A Convertible Preferred Stock	(2)	06/30/2025		C			164.77	(2)	(2)	Common Stock	16,477	(2)	49,514.39	I	See Footnote(3)

1. Name and Address of Reporting Person^*

GLENCORE INTERNATIONAL AG

(Last) (First) (Middle)

BAARERMATTSTRASSE 3

P.O. BOX 1363

(Street)

BAAR V8 CH-6341

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Glencore AG

(Last) (First) (Middle)

BAARERMATTSTRASSE 3

P.O. BOX 1363

(Street)

BAAR V8 CH-6341

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Glencore plc

(Last) (First) (Middle)

BAARERMATTSTRASSE 3

P.O. BOX 1363

(Street)

BAAR V8 CH-6341

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Represents shares of Common Stock acquired upon conversion of 164.77 shares of Series A Convertible Preferred Stock on June 30, 2025.

2. 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.

3. 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.

	GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Director By: /s/ Steven Kalmin Name: Steven Kalmin Title: Director	07/02/2025
	GLENCORE AG By: /s/ Martin Haering Name: Martin Haering Title: Director By: /s/ Carlos Perezagua Name: Carlos Perezagua Title: Director	07/02/2025
	GLENCORE PLC By: /s/ John Burton Name: John Burton Title: Company Secretary	07/02/2025
	** 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).
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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.

FAQ

What did Glencore report in the latest CENX Form 4?

Glencore converted 164.77 Series A preferred shares into 16,477 common shares on 06/30/2025.

How many Century Aluminum shares does Glencore now own?

The filing lists 12,554,508 common shares held indirectly through Glencore AG.

Was there any sale of CENX stock by Glencore?

The excerpt mentions a 27,500,000-share line marked “D,” but it lacks transaction details; no confirmed sale is disclosed.

What is the conversion ratio of Series A preferred stock to CENX common stock?

Each preferred share converts into 100 common shares; the preferred stock has no expiration date.

Does this filing affect Glencore’s 10% owner status?

No. The incremental 16.5 k shares are immaterial and Glencore remains a >10% beneficial owner.