We have some exciting news to share! The Motley Fool UK has now become 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. We’ll be introducing a new name and brand over the coming weeks — we're very excited to share it with you and embark on this new chapter together!

Why a Cash ISA could be your biggest retirement savings mistake

The stock market crash may have put off investors and turned them towards Cash ISAs. I think this is a mistake and could make their retirements poorer.

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.

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.

Cash ISAs can have their place in an investment plan, but banking on them to build wealth for retirement could be a mistake. A Cash ISA could be ideal for depositing money that may be needed at a moment’s notice, and the nominal value of the investment will not go down. But they offer little in the way of growth potential, and may not keep pace with inflation.

Betting on a Cash ISA to fund a comfortable retirement could leave an investor very disappointed. Because of the current low-interest-rate environment, Cash ISAs are struggling to beat inflation. That means the money in a Cash ISA can lose purchasing power.

It has been suggested that the low-interest rates faced today are a result of the financial crisis of 2007–09, and that, eventually, interest rates should begin to return to ‘normal’.

Bank of England historical rates

The chart above was produced by the Bank of England.

The financial crisis did prompt rate slashing, but interest rates had been declining for decades before that. There is no requirement for rates to be above inflation and no reason to suggest that today’s low rates are not the new normal.

Market growth

Investing in the stock market is a cornerstone of retirement planning. Stocks and shares have historically delivered significantly higher returns than Cash ISAs when the investment horizon is long enough.

As I said earlier, Cash ISAs would be ideal for ensuring that the £1,000 put in today is still there in a year or two. Investing in the stock market, via a Stocks and Shares ISA or a SIPP is not without risk. This is particularly true for short-term investments.

Money put to work in the stock market needs to be left alone for perhaps 10 year. Saving for retirement is a great case for stock market investing.

The FTSE All-Share index represents at least 98% of the stock market capitalisation of all UK companies. The index also had an average dividend yield of 3.4% between 1995 and 2020. Investing £1,000 in this index for 10 years at a time between 1995 and 2020 had a 98.9% success rate.

To beat inflation, assumed to be 2% per year, a £1,000 investment needs to grow to at least £1,219 over 10 years. On average, a £1,000 10-year investment made between 1995 and 2020 would have grown to £1,881. Investing in the FTSE All-Share index would have beaten inflation 92% of the time.

The 1.1% of 10-year investments that were losers began around the 1999 market peak and ended in the depths of the financial crisis. It is comforting to know that extending the investment horizon by a year or two did reverse the losses.

Cashing out

For those trying to build serious wealth for retirement, investing in the stock market is a sensible choice. Right now, the stock markets are in a slump but don’t let this put you off. As we have seen, investing when the market is peaking is something to avoid. This latest crash is an opportunity to increase the odds of long-term success. It will always be a mistake to rely on a Cash ISA to build retirement wealth.

James J. McCombie has no position in any of the shares mentioned. 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

One English pound placed on a graph to represent an economic down turn
Investing Articles

Are we approaching a full-blown stock market crash?

Despite the war in Iran, we've avoided a stock market crash so far. Harvey Jones is gearing up to buy…

Read more »

Young mixed-race couple sat on the beach looking out over the sea
Investing Articles

This S&P 500 giant is building a global super app

If this household S&P 500 company achieves its ultimate aim, it could become a hell of a lot bigger in…

Read more »

Friends at the bay near the village of Diabaig on the side of Loch Torridon in Wester Ross, Scotland. They are taking a break from their bike ride to relax and chat. They are laughing together.
Investing Articles

How to target a £1m Stocks and Shares ISA by investing £511 a month

Fancy becoming a Stocks and Shares ISA millionaire? Harvey Jones thinks this long-term investment strategy could help you get there…

Read more »

A senior group of friends enjoying rowing on the River Derwent
Investing Articles

How much do investors need in an ISA to target a £31,353 yearly passive income

Harvey Jones shows how building a portfolio of FTSE 100 shares can generate enough passive income to enjoy a truly…

Read more »

Man smiling and working on laptop
Investing Articles

These 3 ‘secret’ dividend shares could be top stocks to buy in May!

Forget FTSE 100 dividend shares. And look past the FTSE 250 for passive income. Here are three lesser-known dividend stocks…

Read more »

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

How much is needed in an ISA for a £35,828 passive income from FTSE shares?

Royston Wild reveals how a Stocks and Shares ISA invested in FTSE 100 shares could deliver a huge passive income…

Read more »

Hydrogen testing at DLR Cologne
Investing Articles

17% below their 52-week high, is now an opportunity to consider Rolls-Royce shares?

Rolls-Royce Holdings shares have fallen significantly since March. James Beard asks whether now could be a good time for latecomers…

Read more »

Thoughtful man using his phone while riding on a train and looking through the window
Investing Articles

Just Released: Our Top Defence Stock For ISAs In May 2026 [PREMIUM PICKS]

Fire stock picks will tend to be more adventurous and are designed for investors who can stomach a bit more…

Read more »