More investors are becoming ISA millionaires – where are they putting their money?

The number of ISA millionaires is on the rise as investors benefit from time in the stock market.

Data from Hargreaves Lansdown (HL) shows the investment platform has 1,160 ISA millionaires as of May 2024, up from 836 in March.

Other investment platforms including interactive investor and AJ Bell have also reported an increase in stocks and shares ISA millionaires.

Investment platform interactive investor said it had 1,331 ISA millionaires as of June 2024, up from 1,001 in January.

While many HL investors are opting for UK equities, one of the keys to their financial success is building a globally-diversified portfolio of funds and shares.

Additionally, keeping assets in an ISA wrapper is a great way to build wealth as any returns from the best stocks and top funds are tax-free.

Keeping your tax liability down is especially important amid frozen tax thresholds and falling capital gains allowances.

We reveal where to invest if you want to become an ISA millionaire.

Where are ISA millionaires investing?

Hargreaves Lansdown says the average age of its ISA millionaires is 74 but there is no magic formula or fund that they have put money into.

Its platform data shows 44.7% of its ISA millionaires have invested in UK equities and 45.8% in global, while 8.5% have backed the US and 1% put money into gilts.

Among its other ISA clients, 38.5% have money in UK stocks, 51.5% globally, 9.5% in the US and 0.6% in gilts.

"HL ISA millionaires have most of their money invested in equities, but within this they are well diversified globally," says Victoria Hasler, head of fund research at Hargreaves Lansdown.

"They tend to have a higher proportion invested in the UK than non-millionaires. Non-millionaires prefer global and US equities."

The Artemis Income fund is the most popular UK fund among ISA millionaires, returning 89.42% over the 10 years to the end of May 2024, which is more than 10% ahead of the FTSE All Share Index.

Another firm favourite with HL ISA millionaires is the Fidelity Special Situations fund, up 98.04% over the 10 years to the end of May – more than 20% ahead of the benchmark.

There is also plenty of overlap with non-ISA millionaires when it comes to funds to invest in, with both favouring Artemis Income as well as Fundsmith Equity and Lindsell Train Global Equity.

The main difference appears to be how long they have invested for.

“Sadly, there is no quick fix to becoming an ISA millionaire,” says Hasler.

“The main difference between the millionaires and non-millionaires is their age.

“The average age of an HL ISA millionaire is 74, compared to the average age of regular stocks and Shares ISA investors of 51. It’s that old chestnut of time in the market again.”

How to become an ISA millionaire

Investing is a long-term game so don’t expect to get rich quick with an ISA.

Performance can be volatile but by staying invested you benefit from the power of compounding.

If you can invest the full £20,000 annual ISA allowance each tax year and get a 5% return before fees, you could hit the million-pound mark in 25 years with a pot worth £1,002,269.08.

An annual return of 7% could get you to the million-pound target within 22 years, while a more conservative 3% would take 31 years.

“Starting your ISA investing early is a key component to joining the ISA millionaire club,” adds Hasler.

“Other important steps to getting the best returns and seeing that money grow are using your ISA allowance every year, investing wisely and regularly, then leaving the money there."