WESTLAKE CORP (WLK) stock intrinsic value fair value estimate & owner earnings analysis

Westlake Corporation manufactures the building blocks of modern life -- polyethylene, PVC, caustic soda and related petrochemicals -- and converts part of that output into finished pipe, siding, decking, windows and other housing products through its Housing and Infrastructure Products segment. Its core Performance and Essential Materials segment sits on an integrated U.S. Gulf Coast production chain running from ethylene through chlorine and PVC, a structural cost advantage that has historically let it earn through weak pricing periods. The industry it sells into is deeply cyclical, and the last decade shows it clearly. Owner earnings -- the cash the business generates after the capital spending needed just to keep running, before any spending on growth -- rose from about $8.50 a share in 2018 to nearly $21 a share in the 2021-2022 post-pandemic pricing spike, then fell to roughly negative $3 a share in 2025, the weakest year we reviewed. 2025 was also the year the company recorded a $727 million non-cash write-down of goodwill tied to its North American chlor-vinyls business (PVC and caustic soda), and took roughly $640 million in closure and write-off charges shutting higher-cost plants -- chlor-alkali, VCM and styrene units at Lake Charles, Louisiana, a PVC plant in Aberdeen, Mississippi, a facility in the Netherlands, and a PVC unit in China. This followed a period of industry-wide oversupply pressuring PVC and caustic soda prices, worsened by imports; the company won new anti-dumping duties on epoxy resin imports from South Korea, Taiwan and Thailand in May 2025 in response. We valued the shares on owner earnings rather than the accounting profit line, because a capital-intensive business like this can show a large paper loss in a year it is still generating real cash -- the 2025 write-down and closure charges did not cost a dollar of cash. Looking across a full price cycle, 2016 through 2025, the middle year's owner earnings worked out to roughly $6.80 a share; that figure holds up whether or not the unusually strong 2021-2022 spike is included, which tells us it is not an outlier-driven number. Three cases: Weak case: industry oversupply persists for years and prices stay depressed even after the announced plant closures take effect. Owner earnings recover only modestly from the 2025 low -- to roughly $3 a share by year four, reflecting that the worst-performing capacity has already been removed, not that the broader market improves -- and we hold that level flat indefinitely, since nothing specific points to further change either way. Central case: the closures already underway reduce fixed-cost drag and the industry's supply overhang eases over several years, a pattern this business has shown before (recoveries after the 2016 and 2020 troughs). Owner earnings climb back to the roughly $6.80-a-share full-cycle level by around year five and hold there. Strong case: the closures leave a smaller, higher-quality set of plants, the new trade protection helps the epoxy business, and the small number of remaining North American PVC and caustic soda producers hold pricing discipline. Owner earnings settle near $11 a share -- well below the unrepeatable 2021-2022 spike, which required pandemic-era stimulus and supply-chain disruption we are not assuming will recur. We discounted these cases at a flat 6%, roughly the long-term government bond yield plus a small cushion -- the same rate used for every company, since the differences between the weak, central and strong cases already reflect the risk. On that basis the shares work out to roughly $46 in the weak case, $103 in the central case and $165 in the strong case. The company carries about $5.6 billion of total debt against $2.7 billion of cash. That is a real cost in a prolonged downturn -- 2025's negative owner earnings would be a cash drain if it persisted -- but the near-term maturity schedule is manageable (about $500 million due in 2026, next due in 2029) and was recently refinanced, so we treat leverage as a factor that worsens the weak case rather than as a near-term solvency concern. Given the width of this cycle -- a swing from about negative $3 to positive $21 a share on our own figures -- the margin-of-safety price sits at a meaningful discount to the central estimate, close to the weak-case value, and assumes owner earnings have turned convincingly positive for two consecutive quarters, confirming the 2025 trough has passed rather than deepened. Finally, a portion of the year-to-year swings in cash flow come from working-capital timing tied to raw-material price movements, which we stripped out to focus on the sustainable trend; and stock-based compensation, though modest here, was treated as a real cost rather than added back.