We have some exciting news to share! The Motley Fool UK has now become The Twelfth Magpie -- an independent, UK-owned company, led by our long-serving UK management team — Mark Rogers, Chris Nials and Heather Adlington. In practical terms, it’s the same team you know, now fully focused on serving our UK readers and members.

Just as importantly, our approach remains unchanged: long-term, jargon-free, and on your side. This site is our new home, and there will be extra tweaks made across the coming few days as we settle in. So if anything looks a little off, please bear with us!

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

Clues to life-changing wealth from the FTSE 100

There are a number of ways a company can get into the FTSE 100. Some of these companies provide clues to the life-changing wealth the stock market is capable of offering.

A senior group of friends enjoying rowing on the River Derwent

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Twelfth Magpie’s Premium Investing Services. Become a member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn more, and get a free 'Best Buy Now' stock!.

I doubt there’s a single adult in the UK who hasn’t heard of the FTSE 100. After all, it regularly features in the mainstream news.

There are a number of ways a company can get into the ‘Footsie’. But one in particular highlights the stock market’s enormous wealth-building potential for investors. Especially those following the long-term approach to investing we advocate here at The Motley Fool.

Should you buy Rolls Royce shares today?

Before you decide, please take a moment to review this report first. Despite ongoing uncertainties from US tariffs to global conflicts, Mark Rogers and his team believe many UK shares still trade at substantial discounts, offering savvy investors plenty of potential opportunities to learn about.

That’s why this could be an ideal time to secure this valuable research – Mark’s analysts have scoured the markets to reveal 5 of his favourite long-term ‘Buys’. Please, don’t make any big decisions before seeing them.

Market cap

The FTSE 100 is an index of the biggest 100 companies listed on the Main Market of the London Stock Exchange.

In this context, biggest doesn’t mean revenues, or profits, or number of employees. It means ‘market capitalisation’. Market cap is calculated by multiplying a company’s share price by the number of shares it has in issue.

For example, top-ranked firm AstraZeneca currently has a share price of £103 and 1.55bn shares in issue. Therefore, its market cap is £160bn.

Other indexes

The FTSE 100 isn’t the UK’s only index. The FTSE 250 (mid-cap index) contains the next biggest 250 companies.

Then there are the FTSE SmallCap and FTSE Fledgling indexes. And hundreds more companies on the less-regulated Alternative Investment Market (FTSE AIM).

All these indexes are based on market cap.

The Footsie’s predecessor

Before the FTSE 100 was established in 1984, the UK’s previous flagship index was a very different animal.

The FT30 — which still exists today but is rarely quoted — is an index of 30 equally weighted companies. It was designed to represent the breadth of the UK economy. And its constituents tend to change infrequently.

Easy entry

In contrast to the FT30, the market-cap, rules-based FTSE 100 gives any company of sufficient size automatic entry into today’s best known UK market index.

And, as I mentioned earlier, there are a number of ways this can happen.

From private to public

A large private- or state-owned company may decide to list on the stock market. For example, Royal Mail Group (recently renamed International Distributions Services) joined the market in 2013.

Once venerated for the speed and magnificence of its stagecoaches, it galloped straight into the FTSE 100.

London calling

There are also instances when a big company on an overseas stock exchange decides to move its listing to London. In the same year Royal Mail joined the market, Coca Cola HBC switched its listing from Greece to the UK.

One of its parent company’s biggest bottling partners, Coca Cola HBC fizzed into the FTSE 100 before you could say ring-pull.

M&A event

A big merger/acquisition event is another way a company can enter the top index. Not so long ago, betting and gaming group Entain was a FTSE 250 company called GVC Holdings.

In 2018, it bought rival and fellow mid-cap firm Ladbrokes Coral. This transformative acquisition catapulted it into the FTSE 100.

Acorns

The above routes into the Footsie don’t particularly highlight the enormous wealth-building potential for investors I referred to earlier.

However, there’s one route that does. Some companies begin their lives on the stock market as small acorns. And by growing over time, move up through the indexes, and ultimately become mighty oaks of the FTSE 100.

Spectacular success

Halma is an engineering group, focused on safety, environmental and health technologies. It entered the FTSE 100 in 2017.

I can’t tell you what its share price and market cap were when it listed on the London Stock Exchange 50 or so years ago. That information is lost to me in the pre-internet mist of time!

However, I can tell you that in 1994, the Independent reported: “A £10,000 investment in the shares any time between 1974 and 1976 would now be worth more than £3.7m.”

The share price was £2.27 at the time of the article. Today, it’s £18.50. I’ll leave you to do the maths on how much further the £3.7m would have swelled since 1994.

Halma’s return is spectacular, but it’s not the only company to have delivered life-changing wealth for long-term investors. Indeed, big winners are more common than you perhaps imagine.

What are the chances?

A study by asset manager Schroders of the decade to the end of December 2021 found that of 915 UK stocks (that began the period with market caps of £150m+) 6.9% — or 1 in 15 — delivered 10-fold or higher returns for investors.

That tells me the chance of bagging a seriously wealth-enhancing stock — even over a one-decade holding period, let alone two or three, or an investing lifetime — is way, way better than finding a needle in a haystack.

Graham has no position in any of the shares mentioned in this article. The Motley Fool UK has recommended AstraZeneca Plc, Halma Plc, and Schroders Plc. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

Investing Articles

Here’s why Babcock and BAE Systems shares got a Burnham boost today

New PM Andy Burnham has announced his cabinet and defence stocks are rising. But where have I got my money:…

Read more »

Investing Articles

3 under-the-radar UK growth shares that are quietly beating the S&P 500 in 2026

Our writer highlights three British growth shares that have made spectacular gains this year, while everyone was distracted by AI…

Read more »

Close-up image depicting a woman in her 70s taking British bank notes from her colourful leather wallet.
Investing Articles

Here’s the passive income 1,000 Greggs shares could deliver per year

This writer plans to hang onto his Greggs shares because he thinks they are undervalued. But he also likes the…

Read more »

A row of satellite radars at night
Investing Articles

This ex-penny stock has crushed Rolls-Royce shares over 5 years! Is there more to come?

With all eyes on Rolls-Royce shares, this growth share with a connection to SpaceX might have gone unnoticed by a…

Read more »

Close-up as a woman counts out modern British banknotes.
Investing Articles

With a 6.4% yield and P/E of 10 is this FTSE dividend stock a hidden passive income gem?

Building a portfolio of solid UK dividend stocks isn't hard. Paul Summers takes a closer look at one high-yielding candidate…

Read more »

Black woman using smartphone at home, watching stock charts.
Growth Shares

At 112p, where next for the Lloyds share price? 168p or 56p?

Jon Smith mulls over the direction going forward for the Lloyds share price, and explains why two very different scenarios…

Read more »

Investing Articles

This dividend stock has a 7.3% yield, and Stocks and Shares ISA investors are buying!

Looking to move from a Cash ISA to a Stocks and Shares ISA to target passive income? Alan Oscroft has…

Read more »

Surprised Black girl holding teddy bear toy on Christmas
Investing Articles

Could Rolls-Royce shares lock in another 34% gain before Christmas?

Mark Hartley takes a look at some of the more optimistic price targets for Rolls-Royce, and considers a best-case scenario.…

Read more »