Looking for a large second income? You could be making a HUGE mistake!

Just saving rather than investing can put a serious dent in one’s long-term wealth. Royston Wild indicates where he’d rather put his cash to target a second income.

| More on:

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.

Senior Couple Walking With Pet Bulldog In Countryside

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.

Individuals can try to build a healthy second income for retirement in a number of ways. Products like the Cash ISA have enjoyed a renaissance more recently as savings rates have perked up.

According to HM Revenue and Customs, the number of Cash ISAs that were subscribed to in 2022/23 rose by a whopping 722,000 year on year, to just under 7.9m. It’s no coincidence that this coincided with the Bank of England starting its interest rate hiking cycle in late 2021.

However, opting to just save cash rather than invest could result in significant missed returns, and the situation may only worsen over time.

Let me show you how.

Rates to drop?

Today, one of the best easy-access Cash ISA on the market offers a healthy 5.12% interest rate. As the chart below shows, the average rate for these tax-friendly products is comfortably ahead of what savers enjoyed between 2011 and 2022.

Savings rates between 2011 and 2024.
Source: Finder

However, rates are tipped to fall steadily across the market as the BoE begins to loosen monetary policy. So leaving all one’s money locked in a savings account could be a massive mistake.

For the sake of this example, let’s say that the best-paying Cash ISA offers a rate of 4% for the next 30 years. A £300 investment each month at this rate would make me £208,215 over the period.

If I then drew down 4% of this each year, I’d have a monthly income of £694.

Better returns

That’s far below what I could be making if I invested in, say, the FTSE 100 or FTSE 250 instead. These UK share indexes have provided an average long-term return of 7% and 11% respectively over the long term.

However, it’s essential to remember that past performance isn’t a reliable guide to future returns. Share investing is much riskier than parking my money in a secure savings account, and I could even make a loss on certain stocks. This is why having a certain amount in savings for emergencies is always a good idea.

Reducing risk

This is also why investing in an exchange-traded fund (ETF) could be a good idea. These financial instruments spread risk by allocating my cash across a wide range of equities.

Based on the above, buying the iShares FTSE 250 UCITS ETF (LSE:MIDD) could be a great idea. By investing my cash across hundreds of different companies, I have exposure to a multitude of industries and geographies, thereby minimising the impact of underperformance in any one particular area.

Top 10 holdings of the iShares FTSE 250 ETF.
Top 10 holdings of the iShares FTSE 250 ETF. Source: iShares

Furthermore, the ETF provides me with a mix of cyclical and defensive shares, which can provide me with a smooth return over time. There is the risk, however, that the fund’s focus on UK shares could be a problem should broader demand for British assets decline.

If the FTSE 250’s long-term return of 11% continues, a £300 monthly investment in this ETF would turn into £841,356 after 30 years, excluding the impact of slight tracking errors.

That would then make me a monthly £2,805 passive income based on a 4% drawdown rate. That’s four times higher than the £694 I’d enjoy by invest in that 4%-yielding Cash ISA mentioned above.

It’s why I plan to continue investing in stocks and funds over simply saving cash.

Royston Wild 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

Close-up of British bank notes
Investing Articles

£5,000 invested in Greggs shares at the start of 2025 is now worth…

This year's been extremely grim for FTSE 250-listed Greggs -- but having slumped more than 40%, could its shares be…

Read more »

Investing Articles

Looking for shares to buy as precious metals surge? 3 things to remember!

Gold prices have been on a tear. So has silver. So why isn't this writer hunting for shares to buy…

Read more »

British Pennies on a Pound Note
Investing Articles

Up 27% in 2025, might this penny share still be a long-term bargain?

Christopher Ruane's happy that this penny share he owns has done well in 2025. But it's still cheaper now than…

Read more »

Two employees sat at desk welcoming customer to a Tesla car showroom
Investing Articles

Here’s what a single share of Tesla stock cost in January – and what it’s worth now!

Tesla stock's moved up this year -- and it's had a wild ride along the way. Christopher Ruane explains why…

Read more »

Rolls-Royce's Pearl 10X engine series
Investing Articles

Rolls-Royce shares have done it again in 2025! But could the party be over?

2025's been another storming year for Rolls-Royce shares -- and this writer missed out! Might it still be worth him…

Read more »

Businessman with tablet, waiting at the train station platform
Investing Articles

Is this the last chance to buy these FTSE 100 shares on the cheap?

Diageo and Barratt Redrow's share prices have tanked. Is this the opportunity investors seeking cheap FTSE 100 shares have been…

Read more »

Young mixed-race woman jumping for joy in a park with confetti falling around her
Investing Articles

Legal & General shares yield a staggering 8.7% – will they shower investors with income in 2026?

Legal & General shares pay the highest dividend yield on the entire FTSE 100. Harvey Jones asks whether there is…

Read more »

A pastel colored growing graph with rising rocket.
Investing Articles

With its 16% dividend yield, is it time for me to buy this FTSE 250 passive income star?

Ithaca Energy’s 16% dividend yield looks irresistible -- but with tax headwinds still blowing strong, can this FTSE 250 passive…

Read more »