[Form 4] CENTURY ALUMINUM CO Insider Trading Activity

Rhea-AI Filing Summary

Agust F. Hafberg, SVP & Chief Commercial Officer of Century Aluminum Co. (CENX), reported a sale of 9,493 shares of common stock on 09/26/2025 at a price of $27.91 per share. After the sale, the filing shows 55,260 shares beneficially owned in a direct capacity, and the reported holdings include unvested restricted stock units granted under the companys Long-Term Incentive Plans. The Form 4 was executed by attorney-in-fact Paul Sharobeem and filed on 09/30/2025. No derivative transactions are reported.

Insights

Financial Analyst

TL;DR: Routine insider sale by a senior officer; not obviously material to company fundamentals.

The sale of 9,493 shares by the SVP & Chief Commercial Officer appears to be a straightforward disposition reducing direct holdings to 55,260 shares. The filing notes inclusion of unvested RSUs in the reported beneficial ownership, which is common for executive compensation. There are no reported option exercises, warrants, or derivative movements that would indicate hedging or complex liquidity events. For investors, this record shows an insider sale but lacks context on tax planning, diversification, or personal circumstances, so it should be interpreted cautiously and not as a definitive signal about corporate performance.

Corporate Governance Expert

TL;DR: Standard Section 16 reporting of an insider sale; disclosure is timely and consistent with compliance norms.

The Form 4 discloses a single non-derivative sale transaction and continues to show a meaningful residual ownership position through direct holdings and unvested RSUs. The report was signed by an attorney-in-fact, which is an acceptable procedural practice when authorized. There are no indications of related-party transactions, material conflicts, or governance red flags in this filing alone. As a governance item, this is routine compliance information rather than a material governance event.

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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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Hafberg Agust F

(Last) (First) (Middle)

C/O CENTURY ALUMINUM COMPANY

1 S. WACKER DRIVE, SUITE 1000

(Street)

CHICAGO IL 60606

(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		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP & Chief Commercial Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/26/2025

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

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

X	Form filed by One Reporting Person
	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	09/26/2025		S		9,493	D	$27.91	55,260(1)	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. Includes unvested RSUs granted to the Reporting Person under the Issuer's Long-Term Incentive Plans.

Remarks:

	/s/ Paul Sharobeem, attorney-in-fact for Agust F. Hafberg	09/30/2025
	** 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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