[Form 4] Westlake Corporation Insider Trading Activity

Rhea-AI Filing Summary

Mark A. McCollum, a director of Westlake Corporation (WLK), converted previously granted restricted stock units into common shares and received a new grant of restricted stock units. On 08/09/2025, 1,128 restricted stock units that had been granted on 08/09/2024 vested and converted one-for-one into 1,128 shares of common stock. After that conversion his reported beneficial ownership of common stock was 9,656 shares.

Separately, on 08/08/2025 he was awarded 2,168 restricted stock units that will vest on 08/08/2026 and convert one-for-one into common shares when they vest. The filing identifies him as a director and shows the holdings as direct beneficial ownership.

Insights

Securities Analyst

TL;DR: Director converted 1,128 RSUs into shares and received 2,168 new RSUs; reported common stock holding is 9,656 shares.

The Form 4 documents a routine insider compensation and vesting event rather than a market-moving sale or purchase. The key figures are the 1,128 RSUs that vested and converted into common shares on 08/09/2025 and the new grant of 2,168 RSUs awarded on 08/08/2025 that vest on 08/08/2026. There is no cash price reported and no sale transactions disclosed. From an investor-relations perspective this increases insider alignment through equity compensation but does not, standing alone, change control or capital structure materially.

Corporate Governance Expert

TL;DR: This is a standard director equity award and vesting; it reflects compensation and retention, with no indicated change in control.

The filing shows conversion of previously granted RSUs and issuance of new RSUs with a one-for-one conversion to common stock and a one-year vesting horizon for the new award (vesting on 08/08/2026). The reporting person is identified as a director and the ownership is reported as direct. These items are typical of director compensation programs and, based on the disclosed amounts (1,128 shares vested; 2,168 RSUs granted), do not represent a material transfer of control or a dilution event large enough by themselves to be classified as materially impactful to investors.

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^*

MCCOLLUM MARK A

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/08/2025

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	08/09/2025		M		1,128	A	(1)	9,656	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
Restricted Stock Units	(1)	08/08/2025		A		2,168		(2)	(2)	Common Stock	2,168	$0	2,168	D
Restricted Stock Units	(1)	08/09/2025		M			1,128	(3)	(3)	Common Stock	1,128	$0	0	D

Explanation of Responses:

1. Restricted stock units convert into the Issuer's common stock on a one-for-one basis.

2. All of the restricted stock units will vest on August 8, 2026.

3. On August 9, 2024 the reporting person was granted 1,128 restricted stock units vesting on the first anniversary of the grant date.

	Mark A. McCollum by J Feng POA	08/11/2025
	** 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).
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.

FAQ

What transactions did Mark A. McCollum report for WLK on this Form 4?

The Form 4 reports that 1,128 restricted stock units vested and converted into 1,128 common shares on 08/09/2025, and that he was granted 2,168 new restricted stock units on 08/08/2025.

How many shares does Mark A. McCollum beneficially own after the reported transaction?

After the conversion reported on the form his beneficial ownership of common stock is listed as 9,656 shares.

When do the newly granted RSUs vest?

The 2,168 restricted stock units granted on 08/08/2025 are stated to vest on 08/08/2026 and convert one-for-one into common stock.

What was the origin of the 1,128 RSUs that converted to shares?

The filing explains those 1,128 RSUs were granted on 08/09/2024 and vested on the first anniversary of that grant, converting into common stock on 08/09/2025.

Is the reported ownership direct or indirect?

The filing lists the ownership form for the reported shares and RSUs as Direct (D).

What is the reporting person's relationship to WLK?

The reporting person, Mark A. McCollum, is identified on the form as a Director of Westlake Corporation.