What it takes to be an ISA Super Investor

Laura Suter

We take a look at the ISA ‘Super Investors’ that have built Stocks and shares ISA portfolios worth £1 million or more, as well as Junior ISAs that have hit the £100,000 mark and Lifetime ISAs worth £50,000 or more.

With an average age of 70, many ISA Super Investors with AJ Bell will have built their portfolio over decades and may have originally held investments in Personal Equity Plans (PEPs) before the introduction of ISAs over a quarter of a century ago.

Most ISA millionaires are in their 60s and 70s, illustrating the crucial impact of compound returns over the long-term. Nonetheless, nearly a fifth of ISA millionaires have hit the milestone before their 60th birthday. Some successful ISA investors have even managed to accrue an ISA million before turning 40.

The youngest ISA millionaire on the platform is just 35 years old. Astonishingly, a handful of extremely successful ISA investors in their 40s have racked up portfolios worth over £3 million. Although, it’s worth pointing out those with a sizeable portfolio at such a young age often tend to pursue a high conviction strategy focused on specific stocks, which won’t be for everyone.

A number of ISA millionaires are in their 90s, with some closing in on becoming ISA millionaire centurions, demonstrating that for many people long-term ISA investing will mean they’re able to leave a sizeable financial legacy for their family.

ISA millionaires on the AJ Bell platform by age

age of AJ Bell ISA millionaires

Source: AJ Bell

The Super Investors tend to be much more likely to hold shares than the typical investor. Among the ISA millionaires on AJ Bell’s platform, the account holders average 87% in shares (including investment trusts), with most of the rest in funds. By comparison, the figure is 33% across other ISA holders.

Oil giant Shell is the single most popular stock among the wealthiest ISA investors, retaining top spot among the list of most popular ISA holdings.

ISA Super Investors hold on average 25 different positions within their portfolios, although this differs dramatically from one investor to the next. Some hold over 150 different investments, while a handful have just a single investment in their portfolio.

Top 10 holdings among ISA millionaires with AJ Bell

2025 2024
Shell 31% Shell 39%
Lloyds Banking Group 24% Lloyds Banking Group 32%
Aviva 23% GSK 32%
GSK 23% BP 31%
BP 22% Aviva 28%
Legal & General 20% National Grid 25%
National Grid 20% Haleon 25%
HSBC 19% Scottish Mortgage Investment Trust 24%
Scottish Mortgage Investment Trust 19% Legal & General 24%
Diageo 17% HSBC 23%

Source: AJ Bell. Percentage of ISA customers with a balance of £1m or more holding each security.

Junior ISAs

The data also examines Junior ISA holders on the AJ Bell DIY investment platform that have built up a large account worth £100,000 or more.

The youngest JISA holder with £100,000 or more to their name is just five years old, although most are in their teens and many will have benefitted from contributions made to their account since birth.

The JISA Super Investors tend to hold fewer positions in their portfolio than ISA millionaire peers, with the most popular investments including Fundsmith Equity, Scottish Mortgage and F&C Investment Trust, as well as US companies like Tesla, Amazon and Microsoft.

Lifetime ISAs

Lifetime ISAs are one of the most recent iterations of the ISA account, with the government introducing them from April 2017. As a result, investors have had less time to grow such sizeable accounts. Nonetheless, some have built accounts worth more than £50,000.

The youngest Lifetime ISA Super Investor is just 21, putting them within touching distance of the average first time buyer deposit, which according to Halifax is around £60,000.

Some of the largest Lifetime ISA accounts are worth over £250,000, a remarkable sum and an astonishing return given that investors can only deposit a maximum of £5,000 a year including the government top-up. Like their ISA millionaire peers with the biggest accounts, these investors tend to have backed a small number of high growth stocks, which is a risky investing strategy that can offer huge rewards if you get it right.

But ordinary investors shouldn’t misinterpret this as a sign they ought to back one or two stocks in the hope of hitting the jackpot – this strategy can deliver massive returns but there’s also a danger that the stocks underperform and you lose money. If you pursue a high-risk strategy you must do so with your eyes wide open, and for most people it’s best to hold a diversified mix of investments.

What can you learn from the ISA millionaires?

ISA millionaires are a fascinating group and they can teach us a few things about the basics of investing, as well as providing a tantalising glimpse of what’s possible through a combination of regular contributions, patience and perhaps a bit of good fortune too.

The most obvious lesson is time is a crucial ally when it comes to investing. Most millionaires tend to be older because they’ve benefited from decades of compound growth and years of contributions. If you aspire to amass an ISA million, it’s best to get started as early as possible and do so with a ‘get rich slow’ mindset. It’s true there are examples of the opposite – younger investors with a high-risk appetite who have achieved huge returns – but ordinary investors are normally best served by a diversified portfolio held for the long term.

Second, there is no guaranteed recipe for success. Some investors invest in highly diversified portfolios, while others have just a handful of positions. And while shares and trusts are especially popular among ISA millionaires, there are plenty using funds too. The important thing is to invest in what you feel comfortable with and understand the level of risk you are taking in return for the potential reward.

Finally, the success enjoyed by the Super Investors helps to illustrate the simplicity of ISAs. A straightforward financial product, ISAs allow you to invest in a range of assets in a single account, without worrying about dealing with the tax headache of income, dividend or Capital Gains taxes. Your total return is free from the taxman so you can invest hassle-free.

These articles are for information purposes only and are not a personal recommendation or advice. The value of your investments can go down as well as up and you may get back less than you originally invested. Past performance isn't a guide to future performance. Tax and ISA rules apply and could change in future.

Written by:
Laura Suter
Director of Personal Finance

Laura Suter is AJ Bell's Head of Personal Finance. She joined the company in 2018 and is the go-to spokesperson on all things personal finance - from cash savings rates to saving for children and how to invest for the first time. Laura has a degree in Journalism Studies from the University of Sheffield.

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