Stock Analysis

Is Costain Group PLC (LON:COST) Trading At A 40% Discount?

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Key Insights

  • Using the 2 Stage Free Cash Flow to Equity, Costain Group fair value estimate is UK£2.28
  • Costain Group's UK£1.38 share price signals that it might be 40% undervalued
  • Analyst price target for COST is UK£1.53 which is 33% below our fair value estimate

How far off is Costain Group PLC (LON:COST) from its intrinsic value? Using the most recent financial data, we'll take a look at whether the stock is fairly priced by projecting its future cash flows and then discounting them to today's value. We will use the Discounted Cash Flow (DCF) model on this occasion. Before you think you won't be able to understand it, just read on! It's actually much less complex than you'd imagine.

We would caution that there are many ways of valuing a company and, like the DCF, each technique has advantages and disadvantages in certain scenarios. If you want to learn more about discounted cash flow, the rationale behind this calculation can be read in detail in the Simply Wall St analysis model.

Crunching The Numbers

We use what is known as a 2-stage model, which simply means we have two different periods of growth rates for the company's cash flows. Generally the first stage is higher growth, and the second stage is a lower growth phase. To start off with, we need to estimate the next ten years of cash flows. Where possible we use analyst estimates, but when these aren't available we extrapolate the previous free cash flow (FCF) from the last estimate or reported value. We assume companies with shrinking free cash flow will slow their rate of shrinkage, and that companies with growing free cash flow will see their growth rate slow, over this period. We do this to reflect that growth tends to slow more in the early years than it does in later years.

Generally we assume that a dollar today is more valuable than a dollar in the future, and so the sum of these future cash flows is then discounted to today's value:

10-year free cash flow (FCF) estimate

2025202620272028202920302031203220332034
Levered FCF (£, Millions) UK£29.7mUK£31.8mUK£39.0mUK£39.3mUK£39.9mUK£40.6mUK£41.4mUK£42.2mUK£43.2mUK£44.2m
Growth Rate Estimate SourceAnalyst x5Analyst x5Analyst x5Est @ 0.88%Est @ 1.38%Est @ 1.72%Est @ 1.97%Est @ 2.14%Est @ 2.26%Est @ 2.34%
Present Value (£, Millions) Discounted @ 8.2% UK£27.4UK£27.2UK£30.8UK£28.7UK£26.9UK£25.3UK£23.9UK£22.6UK£21.3UK£20.2

("Est" = FCF growth rate estimated by Simply Wall St)
Present Value of 10-year Cash Flow (PVCF) = UK£254m

The second stage is also known as Terminal Value, this is the business's cash flow after the first stage. The Gordon Growth formula is used to calculate Terminal Value at a future annual growth rate equal to the 5-year average of the 10-year government bond yield of 2.5%. We discount the terminal cash flows to today's value at a cost of equity of 8.2%.

Terminal Value (TV)= FCF2034 × (1 + g) ÷ (r – g) = UK£44m× (1 + 2.5%) ÷ (8.2%– 2.5%) = UK£807m

Present Value of Terminal Value (PVTV)= TV / (1 + r)10= UK£807m÷ ( 1 + 8.2%)10= UK£368m

The total value is the sum of cash flows for the next ten years plus the discounted terminal value, which results in the Total Equity Value, which in this case is UK£622m. The last step is to then divide the equity value by the number of shares outstanding. Compared to the current share price of UK£1.4, the company appears quite undervalued at a 40% discount to where the stock price trades currently. The assumptions in any calculation have a big impact on the valuation, so it is better to view this as a rough estimate, not precise down to the last cent.

dcf
LSE:COST Discounted Cash Flow June 17th 2025

The Assumptions

We would point out that the most important inputs to a discounted cash flow are the discount rate and of course the actual cash flows. If you don't agree with these result, have a go at the calculation yourself and play with the assumptions. The DCF also does not consider the possible cyclicality of an industry, or a company's future capital requirements, so it does not give a full picture of a company's potential performance. Given that we are looking at Costain Group as potential shareholders, the cost of equity is used as the discount rate, rather than the cost of capital (or weighted average cost of capital, WACC) which accounts for debt. In this calculation we've used 8.2%, which is based on a levered beta of 1.096. Beta is a measure of a stock's volatility, compared to the market as a whole. We get our beta from the industry average beta of globally comparable companies, with an imposed limit between 0.8 and 2.0, which is a reasonable range for a stable business.

Check out our latest analysis for Costain Group

SWOT Analysis for Costain Group

Strength
  • Earnings growth over the past year exceeded the industry.
  • Currently debt free.
  • Dividends are covered by earnings and cash flows.
Weakness
  • Earnings growth over the past year is below its 5-year average.
  • Dividend is low compared to the top 25% of dividend payers in the Construction market.
Opportunity
  • Annual revenue is forecast to grow faster than the British market.
  • Good value based on P/E ratio and estimated fair value.
Threat
  • Annual earnings are forecast to grow slower than the British market.

Next Steps:

Valuation is only one side of the coin in terms of building your investment thesis, and it ideally won't be the sole piece of analysis you scrutinize for a company. It's not possible to obtain a foolproof valuation with a DCF model. Preferably you'd apply different cases and assumptions and see how they would impact the company's valuation. For instance, if the terminal value growth rate is adjusted slightly, it can dramatically alter the overall result. What is the reason for the share price sitting below the intrinsic value? For Costain Group, there are three relevant items you should consider:

  1. Risks: Take risks, for example - Costain Group has 1 warning sign we think you should be aware of.
  2. Future Earnings: How does COST's growth rate compare to its peers and the wider market? Dig deeper into the analyst consensus number for the upcoming years by interacting with our free analyst growth expectation chart.
  3. Other Solid Businesses: Low debt, high returns on equity and good past performance are fundamental to a strong business. Why not explore our interactive list of stocks with solid business fundamentals to see if there are other companies you may not have considered!

PS. Simply Wall St updates its DCF calculation for every British stock every day, so if you want to find the intrinsic value of any other stock just search here.

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Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email editorial-team (at) simplywallst.com.

This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.

About LSE:COST

Costain Group

Provides infrastructure solutions for the transportation, energy, water, and defense sectors in the United Kingdom.

Flawless balance sheet and undervalued.

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