We have some exciting news to share! The Motley Fool UK has now become The Twelfth Magpie -- an independent, UK-owned company, led by our long-serving UK management team — Mark Rogers, Chris Nials and Heather Adlington. In practical terms, it’s the same team you know, now fully focused on serving our UK readers and members.

Just as importantly, our approach remains unchanged: long-term, jargon-free, and on your side. This site is our new home, and there will be extra tweaks made across the coming few days as we settle in. So if anything looks a little off, please bear with us!

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.

Here’s the secret to a potential £1m Stocks & Shares ISA at 30!

The Stocks and Shares ISA is a key vehicle for building wealth. Dr James Fox explains how it can be used to target the millionaire milestone at a relatively young age.

| More on:
Close-up image depicting a woman in her 70s taking British bank notes from her colourful leather wallet.

Image source: Getty Images

You’re reading a free article with opinions that may differ from The Twelfth Magpie’s Premium Investing Services. Become a member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn more, and get a free 'Best Buy Now' stock!.

There are between 4,850-5,000 Stocks and Shares ISA millionaires, based on recent data. And I imagine very few of them are under 30. However, this doesn’t mean it’s impossible for someone to achieve millionaire status by this still-young age.

The trick of course is starting early. A Junior Stocks and Shares ISA can be started at any young age before being converted to a normal adult Stocks and Shares ISA when they turn 18. However, by starting an ISA for a loved one at birth, we can truly leverage the power of compound returns.

Should you buy Scottish Mortgage Investment Trust Plc shares today?

Before you decide, please take a moment to review this report first. Despite ongoing uncertainties from US tariffs to global conflicts, Mark Rogers and his team believe many UK shares still trade at substantial discounts, offering savvy investors plenty of potential opportunities to learn about.

That’s why this could be an ideal time to secure this valuable research – Mark’s analysts have scoured the markets to reveal 5 of his favourite long-term ‘Buys’. Please, don’t make any big decisions before seeing them.

Doing the maths

So how does it all work? Well, at first, a parent, grandparent or guardian would have to open a Junior ISA in the name of the child. This can be done through any major UK brokerage. Then comes regular contributions. By constantly contributing to a portfolio, we’re providing the fuel with which to grow wealth.

Turning regular contributions into £1m isn’t easy. However, it’s certainly possible. Here’s one calculation: with £500 of monthly contributions and a 10% annualised return, the portfolio would reach £1.13m within 30 years.

Created at thecalculatorsite.com

Now, this calculation relies on an above-average rate of growth — 10%. However, it’s very feasible when investors focus on building a diverse portfolio of quality stocks. For some, a more realistic long-term average would be 8%.

Of course, anyone running their own portfolio needs to be aware that they can lose money. Share prices can be volatile in the short term, and even well-researched investments may underperform expectations.

Where to invest?

My daughter’s Junior ISA contains mostly stocks, but some investment trusts. The latter adds an additional measure of diversification, especially when the majority of the investments I make are in growth-oriented stocks.

One of the investment trusts she invests in is Scottish Mortgage Investment Trust (LSE:SMT). Plenty of investors had their fingers burned with this trust a few years ago when growth-oriented stocks slumped, and Scottish Mortgage tanked.

 

This happens because Scottish Mortgage shares reflect the value of the trust’s holdings. The top holdings currently include privately-held SpaceX, as well as major public names such as MercadoLibre, Meta, Amazon, and Nvidia.

These companies are the driving forces behind the technological changes, but their valuations are also rather volatile. For Scottish Mortgage, this volatility’s enhanced by gearing — borrowing to invest — which can magnify losses.

However, on a positive note, I’d point to management’s track record of picking the next big winners before most of us have even heard of them. The trust’s shares are up an impressive 2,800% over the past 32 years, representing a very strong rate of return.

While there are plenty of investment trusts out there, I do believe Scottish Mortgage — the UK’s largest trust — is certainly worth considering.

James Fox has positions in Nvidia and Scottish Mortgage Investment Trust Plc. The Motley Fool UK has recommended Amazon, MercadoLibre, Meta Platforms, and Nvidia. 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

Night Takeoff Of The American Space Shuttle
Investing Articles

Up 15%, B&M shares are leading the FTSE 250 higher! Is the comeback on?

It's been a tough few years for battered retailer B&M and its shares. But is the FTSE 250 stock now…

Read more »

Affectionate Asian senior mother and daughter using smartphone together at home, smiling joyfully
Investing Articles

Growth AND dividends? Check out this top cheap penny share!

Looking to get maximum bang for your buck? Consider this white-hot UK penny share with an 11.5% dividend yield and…

Read more »

Smiling young man sitting in cafe and checking messages, with his laptop in front of him.
Investing Articles

Snowflake lit up my ISA last week. Could this AI stock be next?

Edward Sheldon’s ISA got a massive boost last week when Snowflake shares surged 40%. He believes there’s more to come…

Read more »

A senior man using hiking poles, on a hike on a coastal path along the coastline of Cornwall. He is looking away from the camera at the view.
Investing Articles

How much would you need in an ISA to match the new State Pension and get another £12,547 a year?

Harvey Jones says nobody should rely purely on the State Pension to fund retirement. They should also aim to generate…

Read more »

Rear view image depicting a senior man in his 70s sitting on a bench leading down to the iconic Seven Sisters cliffs on the coastline of East Sussex, UK. The man is wearing casual clothing - blue denim jeans, a red checked shirt, navy blue gilet. The man is having a rest from hiking and his hiking pole is leaning up against the bench.
Investing Articles

How much is £9,999 invested in a Cash ISA 9 years ago worth today?

Harvey Jones says the Cash ISA may look tempting but is likely to shrink the value of your money over…

Read more »

Female student sitting at the steps and using laptop
Investing Articles

Are Lloyds shares 23% undervalued?

Lloyds shares have fallen in value since a high reached earlier this year. Could this be a sign the FTSE…

Read more »

happy senior couple using a laptop in their living room to look at their financial budgets
Investing Articles

Here’s why Legal & General is still one of the UK’s most popular SIPP buys

So far in 2026, UK SIPP investors have largely stuck to the same group of favourite FTSE 100 stocks. And…

Read more »

Mature people enjoying time together during road trip
Investing Articles

How have Aviva shares become a dividend juggernaut? 5 reasons why

With a long record of dividend growth and enormous yields, Aviva's shares are in high demand with income investors. Can…

Read more »