A Stocks and Shares ISA is one of the most powerful wealth-building tools available to UK investors. Every penny of growth and dividend is entirely sheltered from tax. And for a 45 year-old with retirement still 23 years away, the compounding potential’s genuinely staggering.

In fact, with the right strategy, putting aside £750 a month could be enough to grow a nest egg ranging from £591.5k all the way to over £4m!

Here’s how.

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Running the numbers

A 45-year-old aiming to retire at 68 has a 23-year runway to build wealth. Assuming the UK stock market continues to deliver an average 8% annualised return, investing £750 a month will compound into a nest egg of £591,548.34 by retirement. And thanks to the ISA, all of this can be enjoyed without HMRC knocking at the door.

That’s a serious sum, especially considering all it takes to earn it is time and consistency. But for investors willing to go further and pick individual stocks, the potential rewards can be drastically different. And looking at the FTSE 100, Halma‘s (LSE:HLMA) one of the most compelling examples over the last two decades.

Since May 2003, the safety, health, and environmental technology group has delivered an annualised return of 19.7%. At that rate, £750 a month doesn’t grow to £591k. It grows to a breathtaking £4,043,030.74.

So what made Halma so extraordinary? And, more importantly, can it continue?

Halma’s secret is deceptively simple: acquire niche, cash-generative businesses in regulatory-driven markets and give them autonomy to grow. Then just rinse and repeat.

Its portfolio of companies spans fire detection, water quality monitoring, medical devices, and industrial safety – all sectors where legislation and human safety needs create durable, recurring demand regardless of the economic cycle.

That model’s compounded quietly for decades. And management’s been disciplined enough to almost never overpay during an acquisition or lose focus on the long-term strategy to chase short-term gains.

Today, global safety regulation’s only tightening, the pool of potential acquisitions remains deep, and Halma’s decentralised operating model gives it a remarkable ability to scale without losing the entrepreneurial culture that drives performance in each subsidiary.

So what could go wrong?

Are there any risks worth watching?

Halma’s acquisition-driven model depends on a steady supply of quality targets at sensible prices. In an environment where private equity competition for niche industrial businesses has intensified sharply, deal pricing has become more challenging.

And overpaying for a string of acquisitions that fail to live up to performance expectations could meaningfully dent returns.

There is also the question of scale. The same compounding that produced those extraordinary returns becomes harder to sustain as the business gets larger. After all, growing a £17bn company at 20% a year is a fundamentally different challenge to growing a £1bn one.

With that in mind, investors expecting another two decades of near-20% growth may be left disappointed. But that doesn’t mean this is no longer an interesting business.

Halma’s track record of being a quality compounder speaks for itself. And for investors looking to build long-term wealth inside a Stocks and Shares ISA, this FTSE stock may still be worth a closer look, even if its future performance may not be as impressive as its past.

Should you invest £5,000 in Halma Plc right now?

When investing expert Mark Rogers and his team have a stock tip, it can pay to listen. After all, the flagship Twelfth Magpie Share Advisor newsletter he has run for nearly a decade has provided thousands of paying members with top stock recommendations from the UK and US markets.

And right now, Mark thinks there are 6 standout stocks that investors should consider buying. Want to see if Halma Plc made the list?

Zaven Boyrazian does not hold any positions in the companies mentioned.