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

Passive income text with pin graph chart on business table
Investing Articles

I asked ChatGPT for its top passive income ideas for 2026 and it said…

Stephen Wright is looking for passive income ideas for 2026. But can asking artificial intelligence for insights offer anything valuable?

Read more »

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

Here’s how a 10-share SIPP could combine both growth and income opportunities!

Juggling the prospects of growth and dividend income within one SIPP can take some effort. Our writer shares his thoughts…

Read more »

Tabletop model of a bear sat on desk in front of monitors showing stock charts
Investing Articles

The stock market might crash in 2026. Here’s why I’m not worried

When Michael Burry forecasts a crash, the stock market takes notice. But do long-term investors actually need to worry about…

Read more »

Person holding magnifying glass over important document, reading the small print
Investing Articles

Is this FTSE 250 retailer set for a dramatic recovery in 2026?

FTSE 250 retailer WH Smith is moving on from the accounting issues that have weighed on it in 2025. But…

Read more »

Young Black woman using a debit card at an ATM to withdraw money
Investing Articles

I’m racing to buy dirt cheap income stocks before it’s too late

Income stocks are set to have a terrific year in 2026 with multiple tailwinds supporting dividend growth. Here's what Zaven…

Read more »

ISA Individual Savings Account
Investing Articles

Aiming for a £1k passive income? Here’s how much you’d need in an ISA

Mark Hartley does the maths to calculate how much an investor would need in an ISA when aiming for a…

Read more »

Two business people sitting at cafe working on new project using laptop. Young businesswoman taking notes and businessman working on laptop computer.
Investing Articles

Is investing £5,000 enough to earn a £1,000 second income?

Want to start earning a second income in the stock market? Zaven Boyrazian breaks down how investors can aim to…

Read more »

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

New to investing? REITs are an excellent way to earn passive income!

Zaven Boyrazian thinks that real estate investment trusts (REITs) could be a great way for investors to boost their passive…

Read more »