Westlake CFO exercises options, sells 17,409 shares

Westlake Corp EVP & CFO Mark Steven Bender reported multiple equity transactions dated February 27, 2026.

Rhea-AI Filing Summary

Westlake Corp EVP & CFO Mark Steven Bender reported multiple equity transactions dated February 27, 2026. He exercised two employee stock options for 6,199 and 6,494 shares, converting them into common stock at exercise prices of $65.8125 and $86.5379 per share.

On the same date, he disposed of 12,693 common shares to the issuer at $98.20 per share and completed open-market sales of 16,988 shares at a weighted average price of $100.91 and 421 shares at $101.515 per share. Following these transactions, he directly owned 44,433 common shares.

Insider Trade Summary

Exercise and sale activity reported; no spread calculated

Exercise and Sale 7 txns

Insider Bender Mark Steven

Role EVP & CFO

Sold 17,409 shs ($1.76M)

Approx. gross sale proceeds $1.76M

Approx. exercise cost $970K

Type	Security	Shares	Price	Value
Exercise	Employee Option (right to buy)	6,199	$0.00	$0.00
Exercise	Employee Option (right to buy)	6,494	$0.00	$0.00
Exercise	Common Stock	6,199	$65.8125	$408K
Exercise	Common Stock	6,494	$86.5379	$562K
Disposition	Common Stock	12,693	$98.20	$1.25M
Sale	Common Stock	16,988	$100.91	$1.71M
Sale	Common Stock	421	$101.515	$43K

Holdings After Transaction: Employee Option (right to buy) — 0 contracts (Direct); Common Stock — 44,433 shares (Direct)

Footnotes (3)

1. F1. Weighted average price. These shares were sold in multiple transactions at prices ranging from $100.38 to $101.36 inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.
2. F2. The stock options are exercisable in three installments of 33%. 33% and 34% on February 14, 2021, 2022 and 2023, respectively.
3. F3. The stock options are exercisable in three installments of 33%, 33% and 34% on February 19, 2022, 2023 and 2024, respectively.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did Westlake Corp (WLK) report for its CFO?

Westlake Corp reported that EVP & CFO Mark Steven Bender exercised stock options and both disposed of shares to the issuer and sold shares in the open market. These transactions combined option exercises with subsequent share sales, changing his directly held common stock balance.

How many Westlake (WLK) shares did the CFO sell in the open market?

Mark Steven Bender sold 16,988 Westlake common shares at a weighted average price of $100.91 and an additional 421 shares at $101.515. These open-market sales followed his exercise of employee stock options into common shares on the same date.

What option exercises did the Westlake (WLK) CFO report on February 27, 2026?

He exercised two employee stock option grants covering 6,199 and 6,494 shares of Westlake common stock. The options were converted at exercise prices of $65.8125 and $86.5379 per share, turning derivative rights into directly held common shares.

Did the Westlake (WLK) CFO transfer any shares back to the company?

Yes. Mark Steven Bender reported a disposition of 12,693 Westlake common shares to the issuer at $98.20 per share. This type of transaction is coded as a disposition to the issuer rather than an open-market trade with public investors.

How many Westlake (WLK) shares does the CFO hold after these transactions?

After exercising options and completing the reported dispositions and open-market sales, Mark Steven Bender directly owned 44,433 shares of Westlake common stock. This figure reflects his updated direct ownership position as of the transaction date disclosed.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 03/02/2026 - 11:35 AM EST Learn about SEC filing dates

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^*

Bender Mark Steven

(Last) (First) (Middle)

2801 POST OAK BLVD., STE. 600

(Street)

HOUSTON TX 77056

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
WESTLAKE CORP [ WLK ]

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)
02/27/2026

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	02/27/2026		M		6,199	A	$65.8125	68,041	D
Common Stock	02/27/2026		M		6,494	A	$86.5379	74,535	D
Common Stock	02/27/2026		D		12,693	D	$98.2	61,842	D
Common Stock	02/27/2026		S		16,988	D	$100.91(1)	44,854	D
Common Stock	02/27/2026		S		421	D	$101.515	44,433	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
Employee Option (right to buy)	$65.8125	02/27/2026		M			6,199	(2)	02/14/2030	Common Stock	6,199	$0	0	D
Employee Option (right to buy)	$86.5379	02/27/2026		M			6,494	(3)	02/19/2031	Common Stock	6,494	$0	0	D

Explanation of Responses:

1. Weighted average price. These shares were sold in multiple transactions at prices ranging from $100.38 to $101.36 inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.

2. The stock options are exercisable in three installments of 33%. 33% and 34% on February 14, 2021, 2022 and 2023, respectively.

3. The stock options are exercisable in three installments of 33%, 33% and 34% on February 19, 2022, 2023 and 2024, respectively.

	M. Steven Bender by J Feng POA	03/02/2026
	** 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.
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