UNITED STATES SECURITIES AND EXCHANGE COMMISSION For the Transition Period from to Commission File No. 001-36567 Westlake Chemical Partners LP Washington, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Exact name of registrant as specified in its charter) Delaware 32-0436529 (State or other jurisdiction of ...