What do Stocks and Shares ISA millionaires know that we don’t?

The one big secret to making a million in a Stocks and Shares ISA is… there’s no big secret. Here’s how successful investors do it.

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.

Young mixed-race woman jumping for joy in a park with confetti falling around her

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.

A new Stocks and Shares ISA year has just started, so we now have a fresh £20,000 ISA allowance.

It’s got me thinking about the secrets of the most successful ISA investors. There are around 2,000 ISA millionaires in the UK. So what do they know that the rest of us don’t?

Well, their secrets are really not too hard to grasp.

The more the merrier

First up, those who can afford to invest more have a better chance of making a million. That much seems obvious. But if we don’t have £20k each year to invest, there’s still a key lesson to learn.

Even just a little more every year can still make a big difference.

Before ISAs, Personal Equity Plans were introduced in 1986. A lot of today’s millionaires started back then, and converted to an ISA in 1999 when those took over.

Long-term gains

That’s 37 years in all. Now, £1,000 per year over that time would mean a total of £37,000 invested. But if we could earn 6% per year on top of that and reinvest any income, it could grow to £131,000. More than a 10th of the way to a million.

Is 6% a year a fair goal? It’s about what the UK stock market has returned over the long term. So remember, every little… erm, can add up to a lot.

Don’t trade

The other key rule of ISA millionaire status is to buy and hold. They don’t try to spot the next quick profit and they don’t trade in and out. That just builds up charges, and even a small drop in our annual return can cost a lot over the years.

Lose just 1% a year in trading costs, and that £131,000 falls to £104,000. Too much trading can bring pain.

So no, the most successful ISA investors buy shares that they want to hold for decades.

Funds and trusts

It’s not all individual stocks though. No, a lot of ISA cash goes into collective investments like funds. And here’s were I see the most striking difference.

In general, a lot of ISA investors go for open-ended managed funds. But, over history, the majority of those have failed to beat the stock market index.

Million pound ISAs, by contrast, have a fair bit more cash in investment trusts instead.

Fund management firms have their owners’ interests at heart. But when we buy investment trust shares, we are the owners.

Equity focus

Many funds bought in ISAs spread their cash across various assets. But investment trusts held by the winners focus mainly on stocks and shares.

Scottish Mortgage Investment Trust is one of the most popular this year, despite a 12-month share price fall. I think that shows how the top ISA investors really are in it for the long term. I guess they see a good future for the US growth stocks it holds.

The secrets

To summarise, millionaire Stocks and Shares ISA investors put as much cash into top quality companies as they can, and hold them for the long term without trading. And they seem to like investment trusts a lot.

That’s not so secret at all, really, is it?

Alan Oscroft has positions in Scottish Mortgage Investment Trust Plc. The Motley Fool UK has no position in any of the shares mentioned. 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

Businessman hand stacking money coins with virtual percentage icons
Investing Articles

£5,000 invested in Tesco shares 5 years ago is now worth this much…

Tesco share price growth has been just part of the total profit picture, but can our biggest supermarket handle the…

Read more »

Investing Articles

Here’s why I’m bullish on the FTSE 100 for 2026

There's every chance the FTSE 100 will set new record highs next year. In this article, our Foolish author takes…

Read more »

Thoughtful man using his phone while riding on a train and looking through the window
Growth Shares

UK interest rates fall again! Here’s why the Barclays share price could struggle

Jon Smith explains why the Bank of England's latest move today could spell trouble for the Barclays share price over…

Read more »

Man hanging in the balance over a log at seaside in Scotland
Investing Articles

2 out-of-favour FTSE 250 stocks set for a potential turnaround in 2026

These famous retail stocks from the FTSE 250 index have crashed in 2025. Here's why 2026 might turn out to…

Read more »

Young female business analyst looking at a graph chart while working from home
Investing Articles

Down over 30% this year, could these 3 UK shares bounce back in 2026?

Christopher Ruane digs into a trio of UK shares that have performed poorly this year in search of possible bargains…

Read more »

Mature people enjoying time together during road trip
Investing Articles

Yields up to 8.5%! Should I buy even more Legal & General, M&G and Phoenix shares?

Harvey Jones is getting a brilliant rate of dividend income from his Phoenix shares, and a surprising amount of capital…

Read more »

Light trails from traffic moving down The Mound in central Edinburgh, Scotland during December
Investing Articles

Up 7.5% in a week but with P/Es below 8! Are JD Sports Fashion and easyJet shares ready to take off?

easyJet shares have laboured in 2025, but suddenly they're flying. The same goes for JD Sports Fashion. Both still look…

Read more »

US Stock

I think this could be the best no-brainer S&P 500 purchase to consider for 2026

Jon Smith reveals a stock from the S&P 500 that he feels has the biggest potential to outperform the index,…

Read more »