X0508 4 2024-02-16 0001262823 WESTLAKE CORP WLK 0001488587 Buesinger Robert F. 2801 POST OAK BLVD., STE. 600 HOUSTON TX 77056 false true false false EVP, HIP, IT & Digital false Common Stock 2024-02-16 4 A false 8592 0 A 25346 D Common Stock 2024-02-19 4 M false 4283 0 A 29629 D Common Stock 2024-02-20 4 F false 4083 129.92 D 25546 D Common Stock 2024-02-20 4 F false 3 135.323 D 25543 D Common Stock 2024-02-20 4 F false 399 137.376 D 25144 D Restricted Stock Units 2024-02-19 4 M false 4283 0 D Common Stock 4283 0 D Represents shares of common stock that vested on February 16, 2024 upon the approval of the Issuer's Board of Directors ("BOD"), and the determination by the Compensation Committee of the BOD, of the satisfaction of performance criteria underlying an award of performance stock units ("PSUs") granted to the Reporting Person on February 19, 2021 under the terms of the Issuer's 2013 Omnibus Incentive Plan. Restricted stock units ("RSUs") convert into the Issuer's common stock on a one-for-one basis. Shares otherwise issuable were withheld to satisfy tax obligations arising out of the vesting of the reporting persons RSUs and PSUs. Weighted average price. These shares were sold in multiple transactions at prices ranging from $135.27 to $135.43 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. Weighted average price. These shares were sold in multiple transactions at prices ranging from $137.33 to $137.44 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. On February 19, 2021, the reporting person was granted 4,283 RSUs vesting on the third anniversay of the grant date. Robert F. Buesinger by J Feng POA 2024-02-21