Over the past 20 years, markets have been happy to provide ‘excitement’: dotcoms, crypto, meme stocks and AI hype cycles are just some examples. But if your aim was simply to grow serious wealth, the best answer may have been far duller, according to leading fund managers at Rathbones Asset Management, a leading specialist in active investment strategies.
Alexandra Jackson, director of equities, Rathbones Asset Management says: “Some of the UK’s most successful long‑term investments don’t sell excitement, disruption or bold visions. They sell unavoidable, regulated, repetitive, or mundane things that few people ever talk about: fire detectors, sausages, cables, even road safety barriers. But they do it exceptionally well.”
Here are seven ‘boring’ UK stocks that could have made you a millionaire if £5,000 was invested in each (a total of £35,000), 20 years ago.
- Halma – £5,000 invested 20 years ago would now be worth around £170,000.
Jackson continues: “Take Halma, the safety and environmental technology group. It sells products designed to meet ever growing safety regulations: smoke alarms, gas sensors, water testing equipment and medical diagnostics. You only notice them when they fail — which is precisely why demand keeps coming back. Over roughly 20 years of steady profit growth and rising dividends, an investment of £5,000 invested back then would give an exciting return.” - Diploma – £5,000 invested 20 years ago would now be worth over £371,000.
Another stock, which would have given a great return over 20 years, says Jackson, is Diploma, “A distributor of seals, cables and technical components is not inventing anything transformative. Instead, it sits quietly in mission‑critical supply chains, helping customers solve practical problems day after day. The result has been relentless cash generation and compounding returns that have turned modest investments into fortunes over time.” - Cranswick – £5,000 invested 20 years ago would now be worth around £72,000.
“Cranswick, a producer of pork, poultry and prepared foods, fits into this group. Hardly thrilling — yet its vertically integrated “farm‑to‑fork” model, pricing discipline and dependable demand have delivered solid double‑digit annual returns across cycles. Not exciting by most yardsticks, but remarkably effective,” says Jackson. - Computacenter – £5,000 invested 20 years ago would now be worth nearly £106,000.
Alan Dobbie, fund manager of the Rathbone Income Fund says, “At first glance, Computacenter looks like a low margin reseller of hardware and software, tied to the ebb and flow of corporate IT spending. In practice, it is a long-term partner embedded deep inside customers’ operations, managing complex IT estates, refresh cycles and critical digital infrastructure. The company’s client relationships focus on operational excellence and disciplined capital allocation have helped it deliver steady earnings growth and strong cash generation over decades. These are the actions that turn a very ordinary sounding business into an exceptional long-term compounder.” - Hill & Smith – £5,000 invested 20 years ago would now be worth over £85,000.
Dobbie continues, “Hill & Smith is a business best known for supplying road safety barriers in the UK, composite utility poles in the US, and galvanising services on both sides of the Atlantic. Its activities certainly qualify as boring. Yet, beneath the surface sits a decentralised mini‑conglomerate that earns consistently high returns on capital. By focusing on niche, regulated end markets, disciplined acquisitions and steady reinvestment, Hill & Smith has compounded value quietly for many years, rewarding patient shareholders.” - Compass – £5,000 invested 20 years ago would now be worth over £71,000.
“Contract catering is unlikely to set investor pulses racing but it can be an outstanding business. Compass Group, the world’s largest contract caterer, serves millions of meals each day across offices, factories, hospitals, schools and sports venues. What looks like a low‑margin, highly operational industry has enabled Compass to build real advantages through scale, decentralised management and long‑standing client relationships. Local teams run sites with autonomy, while the group benefits from global purchasing power, tight cost control and disciplined capital allocation. Over time, this blend has delivered resilient cash flows and steady compounding,” says Dobbie. - 4imprint – £5,000 invested in 4imprint 20 years ago would now be worth around £124,000.
“4imprint operates in an unglamorous corner of marketing but it is a high-quality business, focused on distributing promotional merchandise such as branded water bottles, pens and corporate logo polo shirts, primarily in North America,” Dobbie adds. “The model is asset light and cash generative, delivering consistently high returns on capital. Although marketing budgets are often among the first to be cut in a downturn, this is a well-managed business where execution has been disciplined and shareholder returns have been strong, making it a good example of a simple business done very well.”
Equities are not the only way ‘boring’ can pay: for income-focused investors, fixed income could offer a similarly disciplined route to compounding returns.
Bonds: the other ‘boring’ compounding tool
Fixed income offers another steady route to long-term wealth creation, particularly when income is reinvested and returns are allowed to compound over time.
Bryn Jones, head of fixed income, Rathbones Asset Management says: “If you started 24 years ago with £200,000 invested in a diversified corporate bond portfolio, and earned around 7% per annum, leaving the income to compound, that capital could have grown to just under £1 million. The power here comes from consistency and reinvestment over time.
“What makes bonds compelling today is that a larger share of the potential return is visible upfront through starting yields. Investment‑grade credit and higher‑quality high‑yield bonds are offering yields that can contribute a meaningful portion of total return, before any additional value from security selection or active risk management.
“By reinvesting coupons, investors can let time and compounding do the work. It may not be the most attention‑grabbing narrative, but a disciplined, income‑led approach has historically been an effective way to build wealth over the long term.”
Investors often chase the next big thing, but the experience over decades of leading fund managers suggests wealth can be more reliably built through a less glamourous approach, via stocks offering a strong cash generation and disciplined reinvestment.
(Note: all figures were calculated on how much £5,000 invested in each of these stocks on 30/04/06 would be worth on 30/4/26. Figures are from Bloomberg)