WESTLAKE CORP — Director's Dealing 2018

May 14, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: WESTLAKE CHEMICAL CORP (WLK)
CIK: 0001262823
Period of Report: 2018-05-11

Reporting Person: Bender Mark Steven (EVP and CFO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-11	Common Stock	M	16826	$30.0525	Acquired	32636	Direct
2018-05-11	Common Stock	M	6680	$22.915	Acquired	39316	Direct
2018-05-11	Common Stock	S	23506	$117.33	Disposed	15810	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-05-11	Employee Option (right to buy)	$30.0525	M	16826	Disposed	2022-02-17	Common Stock (16826)	Direct
2018-05-11	Employee Option (right to buy)	$22.915	M	6680	Disposed	2021-02-18	Common Stock (6680)	Direct

Footnotes

F1: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $116.85 to $117.59, inclusive. The reporting person undertakes to provide to Westlake Chemical Corp., any security holder of Westlake Chemical Corp. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2: The stock options are excercisable in three installments of 33%, 33% and 34% on February 17, 2013, 2014 and 2015, respectively.

F3: The stock options are excercisable in three installments of 33%, 33% and 34% on February 18, 2012, 2013 and 2014, respectively.