Costain GroupLSE:COST +2.42%59 Operating Margin % is 5.46% as of Dec. 2025, which is 133% above its 10-year median of 2.34. GuruFocus rates LSE:COST with a GF Score™ of 59/100 and a GF Value™ of £0.78 (Significantly Overvalued). The stock has 5 warning signs investors should review. Among 1,767 Construction companies, Costain Group ranks worse than 60.1% on this metric.
Costain Group (LSE:COST) Operating Margin % Explanation
Just like Gross Margin %, it is important to see a company maintains its operating margin over time. Among the same industry, a company with higher operating margin is more efficient in its operation. It is also more stable during industry slowdown or recessions. Peter Lynch prefers those with higher margins than those with lower margins.
Be Aware
Operating Margin % can be manipulated by adjusting the rate of depreciation, depletion and amortization (DDA).
If a company is facing competition, its Operating Margin % may decline. Often the Operating Margin % declines well before the company's Revenue or even profit decline. Therefore, Operating Margin % is a very important indicator of whether the company is facing problems.
For instance, by 2012, Nokia (NOK)'s problems were well known and its stock had lost more than 90% of its market value since 2007. But Nokias Operating Margin % had already been in decline since 2002, although its Earnings per Share (Diluted) were still rising. Investors who paid attention to Operating Margin % would have avoided this huge loss. The same can be said for Research-in-Motion (RIMM).
Therefore, Operating Margin % is a very important screening filter for GuruFocus. GuruFocus's Buffett-Munger screener requires that the profit margin is either consistent or expanding. The Model Portfolio of the Buffett-Munger screener has outperformed the market every year since inception in 2009.
Costain Group Operating Margin % Related Terms
Costain Group Operating Margin % Historical Data
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The historical data trend for Costain Group's Operating Margin % 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.
LSE:COST vs PWR, FIX, EME: Operating Margin % Comparison
For the Engineering & Construction subindustry, Costain Group's Operating Margin %, along with its competitors' market caps and Operating Margin % 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.
Costain Group Operating Margin % vs Construction Industry
For the Construction industry and Industrials sector, Costain Group's Operating Margin % distribution charts can be found below:
* The bar in red indicates where Costain Group's Operating Margin % falls into.
Operating Margin % - also known as operating income margin, operating profit margin and return on sales (ROS) - is the ratio of Operating Income divided by net sales or Revenue, usually presented in percent.
Costain Group's Operating Margin % for the fiscal year that ended in Dec. 2025 is calculated as
* 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.
Costain Group (LSE:COST) has a Operating Margin % of 5.46% as of Dec. 2025. Operating margin is the ratio of total operating income to net sales. View historical data on Costain Group and its competitors. This is 133% above median its historical median of 2.34. According to the industry distribution chart, Costain Group ranks #1062 out of 1767 companies in the Construction industry, placing it in the top 60.1%.
Is Costain Group's Operating Margin % too high?
Costain Group's current Operating Margin % of 5.46% is 133% above median its 10-year median of 2.34. The Construction industry median Operating Margin % is 5.89. Costain Group's value of 5.46% is 7.3% below this industry median. Based on the distribution chart, Costain Group ranks #1062 out of 1767 companies in the Construction industry, which is below the industry midpoint. Overall, Costain Group has a GF Score™ of 59/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Costain Group's Operating Margin % compare to PWR and FIX?
According to the Construction industry distribution chart, Costain Group ranks #1062 out of 1767 companies for Operating Margin %. This places Costain Group in the lower half of its industry. The industry median Operating Margin % is 5.89. Costain Group's value of 5.46% is 7.3% below this benchmark. While the company's 10-year median is 2.34 vs. the industry median of 5.89, Costain Group 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 Operating Margin % for a Construction company?
The median Operating Margin % among Construction companies is 5.89, based on 1,767 companies in the industry. Companies in the top quartile (top 25%) have a Operating Margin % significantly above this median, while those in the bottom quartile fall well below. However, Operating Margin % should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Costain Group's current Operating Margin % of 5.46% is 7.3% 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 Operating Margin % mean?
A high Operating Margin % can signal that a stock is expensive relative to its fundamentals. Operating margin is the ratio of total operating income to net sales. View historical data on Costain Group and its competitors. For the Construction industry, the median Operating Margin % is 5.89 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Costain Group's current Operating Margin % is 5.46%, which is 133% above median its own 10-year median of 2.34. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Costain Group stock overvalued right now?
Based on GuruFocus' analysis, Costain Group (LSE:COST) is currently considered Significantly Overvalued. The stock's GF Value™ is £0.78, compared to a current price of £2.12 — trading 171.8% above its estimated fair value. The current Operating Margin % is 5.46%, which is 133% above median its 10-year median of 2.34 and 7.3% below the Construction industry median of 5.89. Costain Group's overall GF Score™ is 59/100 with 5 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Operating Margin % calculated?
Operating Margin % is calculated from a company's financial statements. For Costain Group (LSE:COST), the current Operating Margin % is 5.46% as of Dec. 2025. 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 Costain Group (LSE:COST) Overvalued in 2026?
Based on GuruFocus' analysis, Costain Group stock appears to be overvalued.
The current stock price of £2.12 is trading 171.8% above its estimated GF Value™ of £0.78.
GuruFocus considers Costain Group to be Significantly Overvalued.
Key valuation signals for LSE:COST:
Operating Margin %: 5.46% (133% above median its 10-year median of 2.34)
GF Value™: £0.78 vs. price of £2.12 (171.8% above fair value)
Industry Position: 7.3% below the Construction median (#1062 of 1767)
No single metric tells the full story. See the LSE:COST stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Costain Group PLC offers solutions and services. It provides engineering and technology solutions and advisory and development, design, management, project delivery, technology integration and asset optimization and support services to highways, nuclear, oil and gas, power, water sectors, rail. The company has two segments Transportation and Natural resources. The transportation segment covers highways, rail, and nuclear markets and the Natural resources segment comprises of water, power and oil and gas markets. Majority of revenue is from Transportation Segment.
59GF Score
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