WLK

SEC source: 0001140361-17-007937 · doc1.xml · nonDerivative · entry 2

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 118,969

SEC source: 0001140361-17-007936 · doc1.xml · nonDerivative · entry 2

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 274,018

SEC source: 0001140361-17-007945 · doc1.xml · nonDerivative · entry 2

Mangieri George J · CIK 0001298504 · VP & Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,155

SEC source: 0001140361-17-007944 · doc1.xml · nonDerivative · entry 2

Teel Lawrence E. · CIK 0001551480 · SVP, Olefins

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,604

SEC source: 0001140361-17-007942 · doc1.xml · nonDerivative · entry 2

Bender Mark Steven · CIK 0001330417 · Sr VP, CFO and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,243

SEC source: 0001140361-17-007939 · doc1.xml · derivative · entry 3

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 660 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 660 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 660 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007939 · doc1.xml · nonDerivative · entry 1

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,723

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007940 · doc1.xml · derivative · entry 3

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,674 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 1,674 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 1,674 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007940 · doc1.xml · nonDerivative · entry 1

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,829

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007943 · doc1.xml · derivative · entry 3

Kenner Andrew · CIK 0001439749 · VP - Manufacturing

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,674 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 1,674 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 1,674 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007943 · doc1.xml · nonDerivative · entry 1

Kenner Andrew · CIK 0001439749 · VP - Manufacturing

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,229

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007937 · doc1.xml · derivative · entry 4

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 10,274 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 10,274 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 10,274 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007937 · doc1.xml · nonDerivative · entry 1

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 121,806

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007936 · doc1.xml · derivative · entry 4

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 12,838 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 12,838 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 12,838 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007936 · doc1.xml · nonDerivative · entry 1

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 277,540

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007945 · doc1.xml · derivative · entry 3

Mangieri George J · CIK 0001298504 · VP & Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 972 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 972 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 972 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007945 · doc1.xml · nonDerivative · entry 1

Mangieri George J · CIK 0001298504 · VP & Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,475

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007944 · doc1.xml · derivative · entry 3

Teel Lawrence E. · CIK 0001551480 · SVP, Olefins

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,094 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 1,094 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 1,094 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007944 · doc1.xml · nonDerivative · entry 1

Teel Lawrence E. · CIK 0001551480 · SVP, Olefins

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,964

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007942 · doc1.xml · derivative · entry 3

Bender Mark Steven · CIK 0001330417 · Sr VP, CFO and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 3,152 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 3,152 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 3,152 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007942 · doc1.xml · nonDerivative · entry 1

Bender Mark Steven · CIK 0001330417 · Sr VP, CFO and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 71,152

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-17-007938 · doc1.xml · derivative · entry 2

Ederington L. Benjamin · CIK 0001588279 · VP, General Counsel, Corp Secy

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 342 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

F2 · derivative.exercise_date: On February 14, 2014, the reporting person was granted 342 restricted stock units vesting on the third anniversary of the grant date.

F2 · derivative.expiration_date: On February 14, 2014, the reporting person was granted 342 restricted stock units vesting on the third anniversary of the grant date.

SEC source: 0001140361-17-007938 · doc1.xml · nonDerivative · entry 1

Ederington L. Benjamin · CIK 0001588279 · VP, General Counsel, Corp Secy

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,724

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into Issuer's common stock on a one-for-one basis.

SEC source: 0001140361-16-088816 · doc1.xml · derivative · entry 1

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,995

Underlying: Common Stock · 4,995 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-088818 · doc1.xml · derivative · entry 1

Kenner Andrew · CIK 0001439749 · VP - Manufacturing

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,330

Underlying: Common Stock · 3,330 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-088819 · doc1.xml · derivative · entry 1

Mangieri George J · CIK 0001298504 · VP & Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,330

Underlying: Common Stock · 3,330 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-088820 · doc1.xml · derivative · entry 1

Teel Lawrence E. · CIK 0001551480 · SVP, Olefins

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,665

Underlying: Common Stock · 1,665 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-088815 · doc1.xml · derivative · entry 1

Ederington L. Benjamin · CIK 0001588279 · VP, General Counsel, Corp Secy

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,324

Underlying: Common Stock · 8,324 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-088814 · doc1.xml · derivative · entry 1

Bender Mark Steven · CIK 0001330417 · Sr VP, CFO and Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,324

Underlying: Common Stock · 8,324 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of Westlake Chemical Corporation common stock.

F2 · derivative.exercise_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

F2 · derivative.expiration_date: The restricted stock units will vest three years from the date of grant (December 1, 2019).

SEC source: 0001140361-16-087265 · doc1.xml · nonDerivative · entry 3

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 0

F3 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 17, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $54.53 to 54.59, 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 (3) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087265 · doc1.xml · nonDerivative · entry 2

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 300

F2 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 17, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $53.48 to 54.47, 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 (2) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087264 · doc1.xml · nonDerivative · entry 3

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 0

F3 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 17, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $54.53 to 54.59, 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 (3) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087264 · doc1.xml · nonDerivative · entry 2

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 300

F2 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 17, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $53.48 to 54.47, 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 (2) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087265 · doc1.xml · nonDerivative · entry 1

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 10,000

F1 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 16, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $54.15 to 54.90, 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 (1) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087264 · doc1.xml · nonDerivative · entry 1

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 10,000

F1 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 16, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $54.15 to 54.90, 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 (1) to this Form 4.

F4 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-086952 · doc1.xml · nonDerivative · entry 2

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 20,000

F2 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 15, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $52.72 to 53.63, 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 (2) to this Form 4.

F3 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-086951 · doc1.xml · nonDerivative · entry 2

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 20,000

F2 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 15, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $52.72 to 53.63, 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 (2) to this Form 4.

F3 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-087088 · doc1.xml · derivative · entry 7

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,582 shares

Expires 2023-02-15

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: The stock options are exercisable in three installments of 33%, 33% and 34% on February 15, 2014, 2015, and 2016, respectively.

SEC source: 0001140361-16-087088 · doc1.xml · derivative · entry 6

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,334 shares

Expires 2022-02-17

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

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

SEC source: 0001140361-16-087088 · doc1.xml · derivative · entry 5

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 15,358 shares

Expires 2017-02-23

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: The stock options are exercisable in two equal installments on February 23, 2012 and August 23, 2016.

SEC source: 0001140361-16-087088 · doc1.xml · nonDerivative · entry 4

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,063

SEC source: 0001140361-16-087088 · doc1.xml · nonDerivative · entry 3

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,337

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001140361-16-087088 · doc1.xml · nonDerivative · entry 2

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,755

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001140361-16-087088 · doc1.xml · nonDerivative · entry 1

Mattina Michael J. · CIK 0001638948 · Sr. VP, Polyethylene

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,421

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001140361-16-086952 · doc1.xml · nonDerivative · entry 1

Chao James · CIK 0001299505 · Director · Chairman · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 30,000

F1 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 14, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $52.63 to 53.11, 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 (1) to this Form 4.

F3 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-086951 · doc1.xml · nonDerivative · entry 1

Chao Albert · CIK 0001299403 · Director · President & CEO · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · By Mother's Estate

Disclosed balance after: 30,000

F1 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 14, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $52.63 to 53.11, 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 (1) to this Form 4.

F3 · ownership.nature: The person reporting disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

SEC source: 0001140361-16-086475 · doc1.xml · nonDerivative · entry 1

Mangieri George J · CIK 0001298504 · VP & Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,503

F1 · price: In accordance with the Securities and Exchange Commission's No Action Letter dated June 25, 2008, we have aggregated the sales that occurred on November 11, 2016 for ease of reporting. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $52.90 to 52.95, 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 (1) to this Form 4.

SEC source: 0001140361-16-086416 · doc1.xml · derivative · entry 3

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,880 shares

Expires 2022-02-17

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: The stock options are exercisable in three installments of 33%, 33% and 34% on February 17, 2013, 2014 and 2015, respectively.

SEC source: 0001140361-16-086416 · doc1.xml · nonDerivative · entry 2

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,155

SEC source: 0001140361-16-086416 · doc1.xml · nonDerivative · entry 1

Buesinger Robert F. · CIK 0001488587 · Sr. Vice President, Vinyls

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,035

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.