[Form 4] KAISER ALUMINUM CORP Insider Trading Activity

Rhea-AI Filing Summary

Kaiser Aluminum executive vice president and CFO Neal E. West, through the West Family Trust, sold 5,000 shares of common stock on February 23, 2026 in open-market transactions. The weighted average sale price was $121.72 per share, with prices ranging from $120.00 to $125.69.

After this indirect sale, the trust held 12,775 shares, and West’s direct holdings stood at 18,960 shares. A portion of these shares was previously acquired through grants of restricted stock units.

Insider Trade Summary

Net Seller: 5,000 shares ($608,600)

Net Sell 2 txns

Insider West Neal E

Role EVP & CFO

Sold 5,000 shs ($609K)

Type	Security	Shares	Price	Value
Sale	Common Stock, par value $0.01 per share	5,000	$121.72	$609K
holding	Common Stock, par value $0.01 per share	--	--	--

Holdings After Transaction: Common Stock, par value $0.01 per share — 12,775 shares (Indirect, By West Family Trust); Common Stock, par value $0.01 per share — 18,960 shares (Direct)

Footnotes (1)

1. Represents the sale of 5,000 shares in multiple transactions, ranging from $120.00 to $125.69 per share, resulting in a weighted average sale price of $121.72 per share. The reporting person undertakes to provide upon request by the SEC staff, the Registrant, or a security holder of the Registrant, full information regarding the number of shares sold at each separate price within the range. Shares acquired pursuant to grants of restricted stock units.

Form 4 Insider Transactions: What Each Field Means →

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
Estimated average burden
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^*

West Neal E

(Last) (First) (Middle)

1550 WEST MCEWEN DRIVE

SUITE 500

(Street)

FRANKLIN TN 37067

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
KAISER ALUMINUM CORP [ KALU ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/23/2026

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, par value $0.01 per share	02/23/2026		S		5,000	D	$121.72(1)	12,775	I	By West Family Trust
Common Stock, par value $0.01 per share								18,960(2)	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. Represents the sale of 5,000 shares in multiple transactions, ranging from $120.00 to $125.69 per share, resulting in a weighted average sale price of $121.72 per share. The reporting person undertakes to provide upon request by the SEC staff, the Registrant, or a security holder of the Registrant, full information regarding the number of shares sold at each separate price within the range.

2. Shares acquired pursuant to grants of restricted stock units.

	/s/ Cherrie I. Tsai, with power of attorney for Neal West	02/25/2026
	** 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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