Will Costain shares continue their bull run?
Having risen more than fivefold in the past few years and now at a six-year high, independent analyst Alistair Strang shares a view on this well-known construction company.
17th March 2026 07:53
by Alistair Strang from Trends and Targets
It’s unusual to feel the need to declare an interest but my wife has held Costain Group (LSE:COST) shares for nearly 30 years. It has been funny, over the years the company's annual report growing from basically a couple of A4 sheets to a thin brochure which became glossy. Most recently, she received a seriously professional book, an item which made a similar noise to “Good Old Yellow Pages” when it was tossed in an empty wheelie bin.
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While it turns out giving your significant other a bunch of penny shares for their 30th birthday wasn’t exactly received with glee, when one of the companies (Edinburgh Oil & Gas) was taken over, she found herself able to buy a Mazda MX5 convertible which she grudgingly admitted was a nice belated 30th birthday present.
From memory, her Costain shares were around 10p each and (partially) thanks to the share split in 2010, she will probably start following our analysis on price movements. She already has a plan to take our grand-daughters on an extravagant shopping spree!
From a relatively near-term perspective, above 199p suggests the potential of a lift to an initial 206p with our secondary, if beaten, at a very confident looking 217p. This 217p is important, the share price closing at or above such a level giving a strong indication a new Big Picture cycle has commenced, one where a future 390p exhibits itself as an attraction.
Our alternate scenario, if things decide to go wrong, suggests below 156p should be capable of causing trouble, calculating the potential of reversal to an initial 138p with our secondary, if broken, at 110p and hopefully a bottom. However, on this share, our inclination is toward optimism for the longer term.
Source: Trends and Targets. Past performance is not a guide to future performance. Important: Trends and Targets charts only incorporate official share count consolidations, ignoring rights issues where investors have a choice as to whether to participate.
Alistair Strang has led high-profile and "top secret" software projects since the late 1970s and won the original John Logie Baird Award for inventors and innovators. After the financial crash, he wanted to know "how it worked" with a view to mimicking existing trading formulas and predicting what was coming next. His results speak for themselves as he continually refines the methodology.
Alistair Strang is a freelance contributor and not a direct employee of Interactive Investor. All correspondence is with Alistair Strang, who for these purposes is deemed a third-party supplier. Buying, selling and investing in shares is not without risk. Market and company movement will affect your performance and you may get back less than you invest. Neither Alistair Strang or Interactive Investor will be responsible for any losses that may be incurred as a result of following a trading idea.
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