The common ASX investing mistake that could cost you thousands

Different investors throughout time make the same errors repeatedly. So don't become one of them.

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, like most other activities in life, requires practice and experience for any human to become competent at it.

In fact, some people may never even reach competency even after years of training.

So when those who have done it successfully for a long time give the newbies advice, it pays to listen.

And there's one ASX investing mistake that experts repeatedly warn about, but novices continue to ignore at their peril.

A close up picture taken from the side of a man with his head face down on his laptop computer keyboard as though he is in great despair over a mistake or error he has made or bad news he has received.

Image source: Getty Images

Stop kidding yourself

It's human nature to want to buy ASX shares at precisely the "right" moment. Everyone wants to buy low and sell high, which is perfectly understandable.

But this is impossible to do intentionally, according to The Motley Fool US' Katie Brockman.

"In reality… it's impossible to know where the market is headed in the short term."

If you attempt to time the market and the stocks go in the opposite direction to what you expect, the results can be disastrous.

"Say you predict stock prices are going to fall in the coming weeks, so you pull your money out of the market now. If the market ends up surging, you'll miss out on those potential earnings," said Brockman.

"Then if you decide to reinvest later after prices have already increased, you'll end up paying a premium for the exact same investments you just sold."

Such mistimings could seem trivial for individual stocks, but it adds up pretty quickly.

"Mistiming the market even once could potentially cost you hundreds or even thousands of dollars, but doing this repeatedly over a lifetime could be far more expensive."

Dollar-cost averaging vs all-in

So, fair enough, timing the market is impossible and dangerous.

Does that mean you buy a little bit regularly, which is a strategy known as dollar-cost averaging, or just invest all at once when your funds allow?

Although dollar-cost averaging seems sensible, evidence shows that simply going all-in provides better returns.

Earlier this year, both Betashares and Morgan Stanley (NYSE: MS) studies came to this same conclusion.

"Lump-sum investing may generate slightly higher annualised returns than dollar-cost averaging as a general rule," said Morgan Stanley portfolio manager Dan Hunt.

The Betashares study calculated who did better on the ASX if they were given $2,000 each year to invest between 2001 and 2022.

The investor who evenly divided the $2,000 into 12 equal monthly investments ended up with a $115,029 portfolio.

The punter who simply bought $2,000 of shares on the first trading day of the year proudly showed off a $118,116 portfolio at the end of the period.

The moral of the story? Don't even think about timing. Just buy ASX shares when you have the savings.

Motley Fool contributor Tony Yoo has no position in any of the stocks mentioned. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has no position in any of the stocks mentioned. The Motley Fool Australia has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.

More on Investing Strategies

a man wearing casual clothes fans a selection of Australian banknotes over his chin with an excited, widemouthed expression on his face.
Growth Shares

3 ASX shares that could double over the next decade (or much sooner)

These shares could be positioned to deliver strong returns in the future. Let's find out why.

Read more »

A young female investor with brown curly hair and wearing a yellow top and glasses sits at her desk using her calculator to work out how much her ASX dividend shares will pay this year
Investing Strategies

3 quality ASX shares to buy for a beginner investor

These beginner-friendly ASX shares offer a mix of quality, growth, and simplicity.

Read more »

Two people work with a digital map of the world, planning their logistics on a global scale.
Index investing

What are the ASX's top 3 index funds for passive investing?

Anyone can buy and hold these index funds forever.

Read more »

A cool young man walking in a laneway holding a takeaway coffee in one hand and his phone in the other reacts with surprise as he reads the latest news on his mobile phone
Cheap Shares

Are '50% off' CSL shares a once-in-a-decade opportunity?

This biotech giant's shares have lost half of their value. Let's see if now is the time to snap them…

Read more »

Man holding fifty Australian Dollar banknotes in his hands, symbolising dividends.
Dividend Investing

3 top ASX dividend share buys for passive income in April

These are my top picks for dividends right now.

Read more »

A golden egg with dividend cash flying out of it
Growth Shares

Forget Easter eggs, these ASX shares could be your best buys this month

These shares could be top buys after the Easter break.

Read more »

Australian dollar notes in the pocket of a man's jeans, symbolising dividends.
Broker Notes

Are CBA shares still a good buy for passive income?

A leading analyst delivers his verdict on CBA’s passive income appeal.

Read more »

A young man talks tech on his phone while looking at a laptop with a financial graph superimposed across the image.
Cheap Shares

3 ASX shares to buy before the next market rally

These shares appear well-placed to rebound with the market when sentiment shifts.

Read more »