Focused on building reliable datasets, financial models, and research tools for value-minded investors. Committed to turning complex data into practical guidance for value-investing and long-term wealth.
Dr. Charlie Tian is the founder and CEO of GuruFocus.com, a leading global investment research platform established in 2004. With a Ph.D. in physics, Dr. Tian transitioned from science to finance, applying a data-driven, disciplined approach to value investing.
WestlakeMEX:WLK 40 Piotroski F-Score is 3 as of Aug. 01, 2026, which is 40% below its 10-year median of 5.00. GuruFocus rates MEX:WLK with a GF Score™ of 40/100 and a GF Value™ of MXN2,091.82 (Fairly Valued). The stock has 4 warning signs investors should review. Among 1,558 Chemicals companies, Westlake ranks worse than 82.8% on this metric.
Warning Sign:
Piotroski F-Score of 3 is low, which usually implies poor business operation.
The zones of discrimination were as such:
Good or high score = 7, 8, 9
Bad or low score = 0, 1, 2, 3
Westlake has an F-score of 3. It is a bad or low score, which usually implies poor business operation.
The historical rank and industry rank for Westlake's Piotroski F-Score or its related term are showing as below:
MEX:WLK'
s Piotroski F-Score Range Over the Past 10 Years
Min: 3 Med: 5 Max: 8
Current: 3
During the past 13 years, the highest Piotroski F-Score of Westlake was 8. The lowest was 3. And the median was 5.
The developer of the system is Joseph D. Piotroski is relatively unknown accounting professor who shuns publicity and rarely gives interviews.
He graduated from the University of Illinois with a B.S. in accounting in 1989, received an M.B.A. from Indiana University in 1994. Five years later, in 1999, after earning a Ph.D. in accounting from the University of Michigan, he became an associate professor of accounting at the University of Chicago.
He wanted to see if he can develop a system (using a simple nine-point scoring system) that can increase the returns of a strategy of investing in low price to book (referred to in the paper as high book to market) value companies.
What he found was something that exceeded his most optimistic expectations.
Buying only those companies that scored highest (8 or 9) on his nine-point scale, or F-Score as he called it, over the 20 year period from 1976 to 1996 led to an average out-performance over the market of 13.4%.
Even more impressive were the results of a strategy of investing in the highest F-Score companies (8 or 9) and shorting companies with the lowest F-Score (0 or 1).
Over the same period from 1976 to 1996 (20 years) this strategy led to an average yearly return of 23%, substantially outperforming the average S&P 500 index return of 15.83% over the same period.
Westlake Piotroski F-Score Related Terms
Westlake Piotroski F-Score Historical Data
* Premium members only.
The historical data trend for Westlake's Piotroski F-Score can be seen below:
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
MEX:WLK vs SOLS, ESI, EMN: Piotroski F-Score Comparison
For the Specialty Chemicals subindustry, Westlake's Piotroski F-Score, along with its competitors' market caps and Piotroski F-Score data, can be viewed below:
* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.
Westlake Piotroski F-Score vs Chemicals Industry
For the Chemicals industry and Basic Materials sector, Westlake's Piotroski F-Score distribution charts can be found below:
* The bar in red indicates where Westlake's Piotroski F-Score falls into.
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
This Year (Mar26) TTM:
Last Year (Mar25) TTM:
Net Income was -2673.746 + -14345.164 + -9795.101 + -3047.526 = MXN-29,862 Mil. Cash Flow from Operations was 2541.942 + 3338.644 + 4051.283 + -1695.074 = MXN8,237 Mil. Revenue was 55602.628 + 52060.84 + 45608.438 + 47822.72 = MXN201,095 Mil. Gross Profit was 4857.934 + 4329.231 + 1566.496 + 2019.662 = MXN12,773 Mil.
Average Total Assets from the begining of this year (Mar25)
to the end of this year (Mar26) was
(423709.78 + 391760.335 + 363471.979 + 359411.778 + 355370.419) / 5 = MXN378744.8582 Mil. Total Assets at the begining of this year (Mar25) was MXN423,710 Mil. Long-Term Debt & Capital Lease Obligation was MXN103,616 Mil. Total Current Assets was MXN107,331 Mil. Total Current Liabilities was MXN49,464 Mil.
Net Income was 5734.192 + 2126.552 + 145.99 + -818.328 = MXN7,188 Mil.
Revenue was 58752.57 + 61374.665 + 59292.755 + 58224.037 = MXN237,644 Mil. Gross Profit was 12164.548 + 9825.46 + 6840.67 + 4746.302 = MXN33,577 Mil.
Average Total Assets from the begining of last year (Mar24)
to the end of last year (Mar25) was
(347857.505 + 386242.732 + 415642.543 + 432755.775 + 423709.78) / 5 = MXN401241.667 Mil. Total Assets at the begining of last year (Mar24) was MXN347,858 Mil. Long-Term Debt & Capital Lease Obligation was MXN108,838 Mil. Total Current Assets was MXN123,179 Mil. Total Current Liabilities was MXN46,747 Mil.
*Note: If the latest quarterly/semi-annual/annual total assets data is 0, then we will use previous quarterly/semi-annual/annual data for all the items in the balance sheet.
Profitability
Question 1. Return on Assets (ROA)
Net income before extraordinary items for the year divided by Total Assets at the beginning of the year.
Score 1 if positive, 0 if negative.
Westlake's current Net Income (TTM) was -29,862.
==> Negative ==> Score 0.
Question 2. Cash Flow Return on Assets (CFROA)
Net cash flow from operating activities (operating cash flow) divided by Total Assets at the beginning of the year.
Westlake's current ratio of this year was 2.16988698. Westlake's current ratio of last year was 2.63501094.
==> Last year's current ratio is higher ==> Score 0.
Question 7. Change in Shares in Issue
Compare the number of shares in issue this year, to the number in issue last year.
Score 0 if there is larger number of shares in issue this year, 1 otherwise.
Westlake's number of shares in issue this year was 127.993. Westlake's number of shares in issue last year was 128.309.
==> There is smaller number of shares in issue this year, or the same. ==> Score 1.
Efficiency
Question 8. Change in Gross Margin
Compare this year's gross margin (Gross Profit divided by sales) to last year's.
Score 1 if this year's gross margin is higher, 0 if it's lower.
Westlake's gross margin of this year was 0.06351897. Westlake's gross margin of last year was 0.14129107.
==> Last year's gross margin is higher ==> Score 0.
Question 9. Change in asset turnover
Compare this year's asset turnover (total sales for the year divided by total assets at the beginning of the year) to last year's asset turnover ratio.
Score 1 if this year's asset turnover ratio is higher, 0 if it's lower
Westlake's asset turnover of this year was 0.47460464. Westlake's asset turnover of last year was 0.68316487.
==> Last year's asset turnover is higher ==> Score 0.
Evaluation
Piotroski F-Score
=
Que. 1
+
Que. 2
+
Que. 3
+
Que. 4
+
Que. 5
+
Que. 6
+
Que. 7
+
Que. 8
+
Que. 9
=
0
+
1
+
0
+
1
+
0
+
0
+
1
+
0
+
0
=
3
Good or high score = 7, 8, 9
Bad or low score = 0, 1, 2, 3
Westlake has an F-score of 3. It is a bad or low score, which usually implies poor business operation.
Westlake (MEX:WLK) has a Piotroski F-Score of 3 as of Aug. 01, 2026. The Piotroski F-score grades a company's business operating strength from 0-9. View historical data on Westlake and its competitors. This is 40% below median its historical median of 5.00. Over the past decade, Westlake's Piotroski F-Score has ranged from 3.00 to 8.00. According to the industry distribution chart, Westlake ranks #1290 out of 1558 companies in the Chemicals industry, placing it in the top 82.8%.
Is Westlake's Piotroski F-Score too high?
Westlake's current Piotroski F-Score of 3 is 40% below median its 10-year median of 5.00. Over the past 10 years, this metric has ranged from a low of 3.00 to a high of 8.00. The Chemicals industry median Piotroski F-Score is 5.00. Westlake's value of 3 is 40% below this industry median. Based on the distribution chart, Westlake ranks #1290 out of 1558 companies in the Chemicals industry, which is in the bottom quartile relative to peers. Overall, Westlake has a GF Score™ of 40/100 and is considered Fairly Valued, reflecting its overall financial health beyond just this single metric.
How does Westlake's Piotroski F-Score compare to SOLS and ESI?
According to the Chemicals industry distribution chart, Westlake ranks #1290 out of 1558 companies for Piotroski F-Score. This places Westlake in the lower half of its industry. The industry median Piotroski F-Score is 5.00. Westlake's value of 3 is 40% below this benchmark. Historically, Westlake's own Piotroski F-Score has ranged from 3.00 to 8.00 over the past decade. While the company's 10-year median is 5.00 vs. the industry median of 5.00, Westlake has consistently been below the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Piotroski F-Score for a Chemicals company?
The median Piotroski F-Score among Chemicals companies is 5.00, based on 1,558 companies in the industry. Companies in the top quartile (top 25%) have a Piotroski F-Score significantly above this median, while those in the bottom quartile fall well below. However, Piotroski F-Score should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Westlake's current Piotroski F-Score of 3 is 40% below the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Piotroski F-Score mean?
A high Piotroski F-Score can signal that a stock is expensive relative to its fundamentals. The Piotroski F-score grades a company's business operating strength from 0-9. View historical data on Westlake and its competitors. For the Chemicals industry, the median Piotroski F-Score is 5.00 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Westlake's current Piotroski F-Score is 3, which is 40% below median its own 10-year median of 5.00. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Westlake stock overvalued right now?
Based on GuruFocus' analysis, Westlake (MEX:WLK) is currently considered Fairly Valued. The stock's GF Value™ is MXN2,091.82, compared to a current price of MXN1,396.00 — trading 33.3% below its estimated fair value. The current Piotroski F-Score is 3, which is 40% below median its 10-year median of 5.00 and 40% below the Chemicals industry median of 5.00. Westlake's overall GF Score™ is 40/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Piotroski F-Score calculated?
Piotroski F-Score is calculated from a company's financial statements. For Westlake (MEX:WLK), the current Piotroski F-Score is 3 as of Aug. 01, 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.
Is Westlake (MEX:WLK) Overvalued in 2026?
Based on GuruFocus' analysis, Westlake stock appears to be undervalued.
The current stock price of MXN1,396.00 is trading 33.3% below its estimated GF Value™ of MXN2,091.82.
GuruFocus considers Westlake to be Fairly Valued.
Key valuation signals for MEX:WLK:
Piotroski F-Score: 3 (40% below median its 10-year median of 5.00)
GF Value™: MXN2,091.82 vs. price of MXN1,396.00 (33.3% below fair value)
Industry Position: 40% below the Chemicals median (#1290 of 1558)
No single metric tells the full story. See the MEX:WLK stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Westlake is a forward-integrated commodity chemicals firm based in Houston. It began as a single low-density polyethylene plant and expanded its capabilities to include ethylene, vinyl chloride monomers, and polyvinyl chloride over the next two decades. The acquisition of Axiall in 2016 made it a North American leader in chlor-alkali and PVC. Today, Westlake has two defined segments: performance and essential materials, and housing and infrastructure products. The HIP segment began operating in 2022 following a series of acquisitions in the building products space. The firm aims to maximize the value of its chemical production by integrating with the HIP segment, realizing the higher margins of finished commercial goods.
40GF Score
Get the complete analysis for MEX:WLK
Piotroski F-Score is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.
Quick Browse
Personalize
Premium Gurus 
Create New Portfolio
MEX:WLK has been successfully added to your 
