TTWF is the owner of 92,010,554 shares of Common Stock of Westlake Corporation. TTWFGP is the owner of an additional 1,395,000
shares of Common Stock of Westlake Corporation and also serves as the General Partner of TTWF and may be deemed to share beneficial ownership of the 92,010,554 shares of Common Stock of which TTWF is the owner.
James Chao is the owner of 62,399 shares of Common Stock, and 68,213 vested Stock Options, as well as 31,119
unvested Stock Options, 10,774 unvested RSUs, and 10,807 unvested PSUs that will vest in favor of James Chao within 60 days of December 31, 2023. The 68,213 vested Stock Options, along with the 31,119 unvested Stock Options that will vest
in favor of James Chao within 60 days of December 31, 2023, are each convertible within 60 days of December 31, 2023, at a ratio of one Stock Option per share of Common Stock. The 10,774 unvested RSUs and the 10,807 unvested PSUs that will
vest in favor of James Chao within 60 days of December 31, 2023, each represent a contingent right to receive one shares of the issuer’s Common Stock within 60 days of December 31, 2023. The foregoing number of PSUs reflects the target
number of PSUs issuable to James Chao pursuant to a February 2021 Performance Stock Unit Award and is subject to adjustment pending final determination of the Issuer’s compensation committee. As of December 31, 2023, the shares of Common
Stock, vested and unvested Stock Options, and unvested RSUs and PSUs of which James Chao is the owner add up to the number of shares listed in Item 9 of James Chao’s respective cover page. James Chao disclaims beneficial ownership of the
shares of Common Stock over which Albert Chao and Dorothy C. Jenkins have sole voting and dispositive power. Based on consideration of the governance principles applicable to TTWF and TTWFGP, James Chao is not a beneficial owner of
shares of Common Stock held by TTWF or TTWFGP.
Dorothy C. Jenkins is the owner of 75,224 shares of Common Stock. As of
December 31, 2023, the shares of Common Stock of which Dorothy C. Jenkins is the owner comprise the number of shares listed in Item 9 of Dorothy C. Jenkins’s respective cover page. Dorothy C. Jenkins disclaims beneficial ownership of the
shares of Common Stock over which Albert Chao and James Chao have sole voting and dispositive power. Based on consideration of the governance principles applicable to TTWF and TTWFGP, Dorothy C.
Jenkins is not a beneficial owner of shares of Common Stock held by TTWF or TTWFGP.
Albert Chao is the owner of 520,148 shares of Common Stock, and 492,936
vested Stock Options, as well as 56,810 unvested Stock Options, 19,810 unvested RSUs, and 19,869 unvested PSUs that will vest in favor of Albert Chao within 60 days of December 31, 2023. The 492,936 vested Stock Options, along with the
56,810 unvested Stock Options that will vest in favor of Albert Chao within 60 days of December 31, 2023, are each convertible within 60 days of December 31, 2023, at a ratio of one Stock Option per share of Common Stock. The 19,810
unvested RSUs and the 19,869 unvested PSUs that will vest in favor of Albert Chao within 60 days of December 31, 2023 each represent a contingent right to receive one shares of the issuer’s Common Stock within 60 days of December 31, 2023.
The foregoing number of PSUs reflects the target number of PSUs issuable to Albert Chao pursuant to a February 2021 Performance Stock Unit Award and is subject to adjustment pending final determination of the Issuer’s compensation
committee. As of December 31, 2023, the shares of Common Stock, vested and unvested Stock Options, and unvested RSUs and PSUs of which Albert Chao is the owner, add up to the number of shares listed in Item 9 of Albert Chao’s respective
cover page. Albert Chao disclaims beneficial ownership of the shares of Common Stock over which James Chao and Dorothy C. Jenkins have sole voting and dispositive power. Based on consideration of the
governance principles applicable to TTWF and TTWFGP, Albert Chao is not a beneficial owner of shares of Common Stock held by TTWF or TTWFGP.