Kaiser Aluminum (KALU) director sells 1,524 common shares

Filing Impact

(Moderate)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

Kaiser Aluminum Corp director Richard P. Grimley reported an open-market sale of 1,524 shares of common stock on April 29, 2026. The weighted average sale price was $171.52 per share, based on multiple trades between $171.25 and $171.74.

Following this transaction, Grimley directly owns 4,578 shares of Kaiser Aluminum common stock. The filing notes he will provide full details of the individual sale prices within the disclosed range upon request from regulators, the company, or its shareholders.

Insider Trade Summary

Net Seller: 1,524 shares ($261,396)

Net Sell 1 txn

Insider Grimley Richard P.

Role null

Sold 1,524 shs ($261K)

Type	Security	Shares	Price	Value
Sale	Common Stock, par value $0.01 per share	1,524	$171.52	$261K

Holdings After Transaction: Common Stock, par value $0.01 per share — 4,578 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares sold: 1,524 shares Weighted average sale price: $171.52 per share Sale price range: $171.25–$171.74 per share +1 more

4 metrics

Shares sold 1,524 shares Open-market sale on April 29, 2026

Weighted average sale price $171.52 per share Common stock sale by director

Sale price range $171.25–$171.74 per share Multiple transactions aggregated in Form 4

Shares owned after transaction 4,578 shares Direct holdings following April 29, 2026 sale

Key Terms

open-market sale, weighted average sale price, Common Stock, par value $0.01 per share, Form 4

4 terms

open-market sale financial

"transaction_action: "open-market sale" for the common stock transaction"

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

weighted average sale price financial

"resulting in a weighted average sale price of $171.52 per share"

Form 4 regulatory

"INSIDER FILING DATA (Form 4): transaction for Kaiser Aluminum"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

Form 4 Insider Transactions: What Each Field Means →

05/01/2026 - 04:40 PM

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^*

Grimley Richard P.

(Last)

(First)

(Middle)

1550 WEST MCEWEN DRIVE, SUITE 500

(Street)

FRANKLIN

TENNESSEE

37067

(City)

(State)

(Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/29/2026

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

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

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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock, par value $0.01 per share	04/29/2026		S		1,524	D	$171.52⁽¹⁾	4,578	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. Represents the sale of 1,524 shares in multiple transactions, ranging from $171.25 to $171.74 per share, resulting in a weighed average sale price of $.171.52 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.

	/s/ Cherrie I. Tsai, with power of attorney for Richard P. Grimley	05/01/2026
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transaction did Kaiser Aluminum (KALU) disclose for Richard P. Grimley?

Kaiser Aluminum disclosed that director Richard P. Grimley sold 1,524 shares of common stock. The sale occurred on April 29, 2026 in open-market transactions, and was reported as a routine Form 4 insider transaction with remaining direct ownership of 4,578 shares.

At what prices did Richard P. Grimley sell Kaiser Aluminum (KALU) shares?

Richard P. Grimley sold 1,524 Kaiser Aluminum shares in multiple trades between $171.25 and $171.74 per share. The weighted average sale price reported was $171.52 per share, reflecting the blended price across all individual transactions executed that day.

How many Kaiser Aluminum (KALU) shares does Richard P. Grimley hold after the sale?

After selling 1,524 shares, Richard P. Grimley directly holds 4,578 Kaiser Aluminum common shares. This post-transaction balance is disclosed in the Form 4 and reflects his continuing equity stake as a director of the company following the April 29, 2026 sale.

What type of transaction was reported in the Kaiser Aluminum (KALU) Form 4?

The Form 4 reports an open-market sale of common stock by director Richard P. Grimley, coded as “S.” This indicates a sale in the market or private transaction, rather than an option exercise, gift, or tax-withholding related disposition of Kaiser Aluminum shares.

Does the Kaiser Aluminum (KALU) Form 4 provide details on each sale price?

The Form 4 discloses a price range and weighted average, not each specific trade price. It states Grimley will provide full information on the number of shares sold at each separate price within the $171.25–$171.74 range upon request from regulators, the company, or shareholders.