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.

How I’d invest £20k in an ISA today

If Edward Sheldon was looking to invest £20k in an ISA right now, there are a few simple moves he’d make to target strong long-term returns.

Middle-aged black male working at home desk

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.

Investing within a Stocks and Shares or Lifetime ISA is one of the best ways to build wealth in the UK. Within these accounts, all gains and income generated are tax-free.

Here, I’m going to explain how I’d invest £20k in an ISA today. These are the moves I’d make in an effort to create long-term wealth.

XXX

Please note that tax treatment depends on the individual circumstances of each client and may be subject to change in future. The content in this article is provided for information purposes only. It is not intended to be, neither does it constitute, any form of tax advice. Readers are responsible for carrying out their own due diligence and for obtaining professional advice before making any investment decisions.

Spreading my risk

If I was putting money to work within an ISA today, one thing I’d certainly do is take a diversified approach to investing.

Diversification is the process of spreading money over many different investments (not putting all of your eggs in one basket). And it can significantly increase the chances of being a successful investor.

While shares tend to generate strong returns over the long term, not every stock is going to do well. For every JD Sports Fashion (up around 70% over the last five years) there’s a BT Group (down around 40% over the same period).

Ultimately, diversification reduces the risk of investing a lot of money in a dud. To diversify, I could buy a range of different stocks with my £20k. Alternatively, I could invest some of my money in funds or investment trusts for instant diversification.

A global approach

I’d also take a global approach to investing. The UK has some world-class companies. Diageo, Unilever, and London Stock Exchange Group are some good examples.

But let’s face it – a lot of the world’s most dominant companies (Apple, Amazon, Alphabet, etc) are listed overseas. And many of these internationally-listed companies are generating strong returns for investors.

Apple, for example, is up about 300% over the last five years.

So I’d spread my £20k across both UK and international shares.

It’s worth noting that buying US shares in an ISA is very easy today. One issue to be aware of however, is foreign exchange rates. If I was to buy a US-listed stock today, and the pound immediately strengthened against the US dollar, my holding would be worth less in GBP terms.

Small-cap stocks for big gains

Finally, I’d invest in both large-cap stocks and small-cap shares.

Investing in large caps has plenty of benefits. Larger companies often pay dividends and their share prices tend to be more stable than small-caps.

But for big gains, it’s hard to beat small-caps. Often, smaller companies are growing at a spectacular rate. Meanwhile, they tend to be less researched, meaning there’s more potential for better-than-expected results and explosive share price movements.

An example of a UK small-cap that has done really well in recent years is Cerillion. Five years ago, it was trading at around 150p. Today however, it’s near 1,300p, meaning a £2k investment has grown into more than £17,000.

Taking a long-term approach

Of course, making these three moves wouldn’t guarantee success. But I reckon that over the long term, this approach to investing £20k should work pretty well.

Ed Sheldon has positions in Alphabet, Amazon.com, Apple, London Stock Exchange Group, Cerillion Plc, Diageo Plc, and Unilever Plc. The Motley Fool UK has recommended Alphabet, Amazon.com, Apple, Cerillion Plc, Diageo Plc, and Unilever Plc. Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool’s board of directors. John Mackey, former CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool’s board of directors. 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

Friends and sisters exploring the outdoors together in Cornwall. They are standing with their arms around each other at the coast.
Investing Articles

£503 buys 14 shares in this FTSE 250 stock that returned 23.9% annually for the last 15 years

This FTSE 250 stock has averaged a huge return for 15 years. At today's price, £503 buys 14 shares. But…

Read more »

Black woman using loudspeaker to be heard
Investing Articles

£1,000 buys 25 shares in this FTSE 100 stock that’s returned 29.2% annually for the last 10 years

This FTSE 100 mining stock has returned close to 30% a year for a decade. At 3,995p, £1,000 buys 25…

Read more »

Female student sitting at the steps and using laptop
Investing Articles

Down 47%, is this growth stock finally worth buying in May?

With a £288m order book and a hidden pipeline of defence and nuclear contracts, is this growth stock now too…

Read more »

House models and one with REIT - standing for real estate investment trust - written on it.
Investing Articles

2 REITs yielding 7%+ to consider for passive income in 2026

A REIT backed by the NHS and another backed by Tesco and Sainsbury's with both yielding 7%+. Here's why I'm…

Read more »

Woman riding her old fashioned bicycle along the Beach Esplanade at Aberdeen, Scotland.
Investing Articles

Just 97 shares of this UK dividend stock generate £238 in passive income

A 5.7% yield, £238 in passive income from just 97 shares, and one of the most divisive dividend stocks on…

Read more »

ISA coins
Investing Articles

£10,000 in an ISA generates a second income of…

The London Stock Exchange is home to some of the world's most generous dividends. But how big a second income…

Read more »

Shot of a senior man drinking coffee and looking thoughtfully out of a window
Investing Articles

Expert recommendations: 2 top income stocks yielding 7%+!

With yields of 7.2% and 7.8% respectively, these two income stocks are catching the eyes of institutional analysts. Should investors…

Read more »

Illustration of flames over a black background
Investing Articles

3 top income-focused stocks to buy in May 2026, according to experts

Looking for a stock to buy for income in May 2026? Experts have flagged these three UK dividend shares as…

Read more »