Long-term ISA investing – the compound effect

When it comes to investing, longer is better, writes Thomas Carr.

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.

Attempting to time the markets to perfection is without doubt one of the biggest and most common mistakes that any investor can make. If hedge funds’ sophisticated AI-driven computer algorithms are unable to do it, then what chance do the rest of us have?

Not only is it virtually impossible to do, but it is also pretty futile. Waiting for a stock to drop another two percent might make you feel like you have bought a bargain, but over a long investment horizon, it isn’t going to make much impact at all. Even worse, investors waiting for the ‘right price’ may miss out on top-quality stocks altogether.

Instead of focusing on timing the markets, investors should concentrate on time in the markets. Long investment holding periods benefit from the power of compounding – basically the principle of interest accumulating on interest. The longer the holding period, the bigger the compound effect.

The table below shows the effect of compounding over time, assuming inflation-adjusted share returns of 5.5% (the average real UK share return from 1969-2018 – including the reinvestment of dividends).

Holding period (years)

£10,000 initial investment

£50,000 initial investment

10

£17,081

£85,407

20

£29,177

£145,887

30

£49,839

£249,197

40

£85,133

£425,665

50

£145,419

£727,098

60

£248,397

£1,241,988

The table shows that the longer the holding period, the larger the incremental monetary increase in the investment value. For example, in the first 30 years, an initial £10,000 investment increases in value by £39,839. But in the 30-60 year holding period, the value of the investment increases by a huge £198,558.

With an initial investment of £50,000, holding an investment for an additional 10 years (from 40 years to 50 years) results in an extra gain of £301,433.

The table also shows – intuitively – that the more that is invested initially, or early on, the better, with investments made later having less time to benefit from compounding. This has huge implications for young people that are contributing to pensions.

From this point of view, it makes sense to contribute as much as possible, as early as possible. It’s an unfortunate irony that earnings are often at their lowest right at the point when it’s most important to be making large contributions, with the reverse also holding true.

The compound effect also demonstrates the value of opening Junior ISAs for young children. Maxing out the savings limit of £4,368 at birth would be worth £141,805 after 65 years (investing at the rate above) – which I’m sure would come in very handy to most retirees!

I think it’s vital that young people understand the benefits of investing at an early age. I would recommend diverting some money towards a stocks and shares ISA, if possible, and investing a regular amount each month. A Lifetime ISA could work just as well, maybe even better. It could make the difference between a comfortable retirement and a difficult one.

For those that are nearer to retirement, and after a bigger pot, it’s important to note that to better the returns outlined above, then it’s likely that investments will have to be less diversified, and thus riskier…

More on Retirement Articles

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 should a 40-year old put into an empty SIPP to aim for a million by 60?

Over the next 20 years, someone could turn a SIPP with nothing in it today into a seven-figure retirement pot.…

Read more »

A senior man and his wife holding hands walking up a hill on a footpath looking away from the camera at the view. The fishing village of Polperro is behind them.
Investing Articles

Match the State Pension through buying dividend shares? Here’s what that might cost

If the State Pension seems like it might not go far enough, some forward planning today could potentially help ease…

Read more »

British flag, Big Ben, Houses of Parliament and British flag composition
Investing Articles

FTSE 100 vs S&P 500: why investing in home-grown stocks may make more sense for retirement

Our writer explains why he prefers FTSE 100 stocks when planning for retirement. But that doesn't mean giving up on…

Read more »

Tŵr Mawr lighthouse (meaning "great tower" in Welsh), on Ynys Llanddwyn on Anglesey, Wales, marks the western entrance to the Menai Strait.
Investing Articles

Target a £15,000 passive income with just £7 a day in a £10k ISA

With a decent lump sum and small daily contributions in an ISA, Mark Hartley outlines a route to earn a…

Read more »

A senior man and his wife holding hands walking up a hill on a footpath looking away from the camera at the view. The fishing village of Polperro is behind them.
Investing Articles

Here’s how you could invest £300 a month for a £38k+ second income

Looking to make a healthy second income to supplement the State Pension? Royston Wild explains the long-term benefit of buying…

Read more »

The words "what's your plan for retirement" written on chalkboard on pavement somewhere in London
Investing Articles

You can aim to double the State Pension for the price of a daily coffee!

Zaven Boyrazian says that by giving up something we might not even miss, we could unlock a passive income in…

Read more »

Group of friends talking by pool side
Investing Articles

How much do you need in a SIPP to aim for a £1,500 monthly passive income?

Zaven Boyrazian explains how SIPP investors can target an extra £1,500 monthly retirement income stream using generous FTSE 100 dividend…

Read more »

A front-view shot of a multi-ethnic family with two children walking down a city street on a cold December night.
Investing Articles

Here’s how you could retire on £1,000,000 with dividend shares!

Looking to build a sizeable nest egg for later life? Royston Wild explains how UK dividend shares could boost your…

Read more »