Westlake Corporation (WLK) Stock

Westlake Corporation (WLK) is a Materials stock trading at $78.91 (as of 2026-08-21), with a market capitalization of $10.11B. Figures are sourced from first-party U.S. SEC EDGAR filings and market data.

Westlake Corporation manufactures and supplies petrochemicals, polymers, and building products worldwide through the Performance and Essential Materials segment and the Housing and Infrastructure Products segment. Its customers include chemical processors, plastics fabricators, construction contractors, municipalities, and supply warehouses serving residential construction and other consumer and industrial markets.

Understand Westlake Corporation: how it makes money

Westlake Corporation makes and supplies petrochemicals, polymers, and PVC building products, and sells them through two business segments, Performance and Essential Materials, and Housing and Infrastructure Products.

Westlake’s profit model depends on the combined contribution of its two operating segments, PEM (petrochemicals and polymers) and HIP (PVC and related building products), as overall results roll up from how each segment turns sales into segment EBITDA.

Revenue by segment (latest quarter)
PEM	$1.7B
HIP	$1.0B

Business quality (Weak): The company’s two-segment structure is clear and supported by segment sales and EBITDA operating metrics, but the provided segment sales data includes multiple variants, so segment-to-total mapping depends on which specific sales line item is used.

Bull case

Diversified end markets by product line: Westlake operates two segments, PEM focused on petrochemicals and polymers (including polyethylene, styrene monomer, PVC and VCM-related products), and HIP focused on residential and infrastructure PVC building products (including PVC siding, trim and moldings, roofing applications, windows, and PVC deck).
Both segments show positive segment EBITDA in the provided KPI set: The dataset includes positive segment EBITDA figures for both Performance and Essential Materials and Housing and Infrastructure Products, suggesting operating contribution from each segment rather than a single-segment profit source.

Bear case

Operating profitability is currently negative: For the quarter ended 2026-03-31, Westlake reported -6.5% operating margin, which indicates that total company operating results were not supported by sufficient operating income despite segment EBITDA being provided.
Profitability may vary meaningfully across segments: The provided segment sales and segment EBITDA figures differ between PEM and HIP, implying that swings in segment performance can change the overall outcome.

Valuation — source: SEC EDGAR (first-party)
Price	$78.91
Market Cap	$10.11B
EV / EBITDA	155.7
Price / Book	1.12
Price / Sales	0.90
FCF Yield	-15.8%
DCF Value (model)	$45.36
DCF Upside vs Price	-42.5%

Profitability & Growth — source: SEC EDGAR
Revenue (TTM)	$11.17B
Net Margin	-13.5%
Revenue Growth (YoY)	-8.0%
EPS Growth (YoY)	-351.1%
FCF Growth (YoY)	-273.2%

Financial Health — source: SEC EDGAR
Altman Z-Score	1.68 (distress)
Piotroski F-Score	3/9 (weak)

Valuation vs Sector & Industry
Sector P/E (Materials)	25.9
Industry P/E (Chemicals)	31.1

Smart-Money Activity — SEC Form 4 / 13F / Congressional disclosures
Top Institutional Holder	Orbis Allan Gray Ltd ($618.39M)
Institutional Holders Tracked	10
Congressional Trades (recent)	3

Company
Sector	Materials
Industry	Chemicals
CEO	Jean-Marc Gilson
Employees	15,540
Country	US
IPO Date	2004-08-12

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Data as of 2026-08-21.

Figures sourced from U.S. Securities and Exchange Commission (SEC EDGAR) filings and market data. Not personalized investment advice.