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.

Meet the monster stock that continues to crush the FTSE 100 index

The FTSE 100 is home to a handful of winning stocks that aren’t exactly household names. Here’s one of the index’s biggest by far.

| More on:
UK supporters with flag

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More.

The FTSE 100’s risen 12.5% in 2025 and 25% over two years, hitting new records along the way. Investors in the index will obviously be very satisfied with this, especially when dividends are thrown into the mix.

However, that’s small potatoes compared to the returns of 3i Group (LSE:III). Shares of the private equity firm have exploded more than 100% higher in two years and 330% over five years. Only Rolls-Royce and NatWest have beaten that in the FTSE 100 since August 2020.

XXX

This certainly disproves the theory that only juicy returns can be delivered across the pond in New York!

3i at a glance

I think it’s fair to say that 3i isn’t a household name. Yet it has a meaty £39bn market-cap, which makes it larger than well-known businesses like Tesco (£28bn) and Vodafone (£21bn).

So how exactly does the firm make money? It does so primarily through buying stakes in unlisted businesses. As they grow (higher sales, profits, and valuations), 3i’s net asset value (NAV) rises. Or vice versa. 

Eventually, it sells these investments, generating capital gains. For example, in June, 3i sold its stake in MPM (a premium cat food manufacturer) for total gross proceeds of about £400m. This was more than triple what it originally invested. 

However, 3i’s portfolio is dominated by Action, which makes up a whopping 71% of it (worth over £19bn). This is the Dutch discount retail chain that’s like a cross between Aldi and Poundland. It’s been expanding aggressively across Europe.

In June, Action opened its 3,000th store. This jewel has driven spectacular outperformance due to 3i’s massive 58% stake in it.

The company also owns 29% of the FTSE 250’s 3i Infrastructure, a stake that was valued at £921m in June. 3i Infrastructure paid 3i Group a £17m dividend in Q1 (covering the three months to 30 June). So it gets regular income from here.

Other portfolio holdings include Royal Sanders, a European manufacturer of personal and home care products, and Baltic Sea ferry operator Scandlines.

Latest quarter

In Q1, the value of the portfolio rose almost 7% quarter on quarter to 2,711p. Action increased sales 18% to €7.4bn in the first half of 2025, with like-for-like sales up 6.8%. It opened 125 new stores and remains on track to add 370 in 2025. It’s going great guns.

The risk here though is that 3i’s currently trading at roughly a 50% premium to NAV. So investors are having to fork out to grab a slice of the action (no pun intended). If anything negative happened to the discount retailer, then 3i shareholders would immediately feel it.

Another thing worth mentioning here is the way Action is valued. To arrive at the value of its stake, 3i applies quite a steep EBITDA multiple for a retailer. Then again, Action regularly delivers strong growth and is taking market share, so this helps justify the valuation. 

Overall, it’s hard not to be impressed with the returns 3i generates. Its roots go back to 1945, so it has its company-picking methodology down to a fine art.

Due to its high quality, I think this is one for investors to keep on the radar, though waiting for a dip might be wiser given the chunky premium.

Ben McPoland has positions in Rolls-Royce Plc. The Motley Fool UK has recommended Rolls-Royce Plc, Tesco Plc, and Vodafone Group Public. 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

Friends and sisters exploring the outdoors together in Cornwall. They are standing with their arms around each other at the coast.
Investing Articles

£503 buys 14 shares in this FTSE 250 stock that returned 23.9% annually for the last 15 years

This FTSE 250 stock has averaged a huge return for 15 years. At today's price, £503 buys 14 shares. But…

Read more »

Black woman using loudspeaker to be heard
Investing Articles

£1,000 buys 25 shares in this FTSE 100 stock that’s returned 29.2% annually for the last 10 years

This FTSE 100 mining stock has returned close to 30% a year for a decade. At 3,995p, £1,000 buys 25…

Read more »

Female student sitting at the steps and using laptop
Investing Articles

Down 47%, is this growth stock finally worth buying in May?

With a £288m order book and a hidden pipeline of defence and nuclear contracts, is this growth stock now too…

Read more »

House models and one with REIT - standing for real estate investment trust - written on it.
Investing Articles

2 REITs yielding 7%+ to consider for passive income in 2026

A REIT backed by the NHS and another backed by Tesco and Sainsbury's with both yielding 7%+. Here's why I'm…

Read more »

Woman riding her old fashioned bicycle along the Beach Esplanade at Aberdeen, Scotland.
Investing Articles

Just 97 shares of this UK dividend stock generate £238 in passive income

A 5.7% yield, £238 in passive income from just 97 shares, and one of the most divisive dividend stocks on…

Read more »

ISA coins
Investing Articles

£10,000 in an ISA generates a second income of…

The London Stock Exchange is home to some of the world's most generous dividends. But how big a second income…

Read more »

Shot of a senior man drinking coffee and looking thoughtfully out of a window
Investing Articles

Expert recommendations: 2 top income stocks yielding 7%+!

With yields of 7.2% and 7.8% respectively, these two income stocks are catching the eyes of institutional analysts. Should investors…

Read more »

Illustration of flames over a black background
Investing Articles

3 top income-focused stocks to buy in May 2026, according to experts

Looking for a stock to buy for income in May 2026? Experts have flagged these three UK dividend shares as…

Read more »