My 5 investing mistakes for newbies to avoid!

Learning about investing isn’t easy, especially if you are a newcomer to this global game. Here are five ways you can learn from my dumb mistakes!

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.

Having been investing in shares for 35 years, I’ve made more than my fair share of howlers. But I’ve learnt from my mistakes over the years. Today, I aim to be a rational, objective investor making sensible decisions about risk and portfolio allocation. Here are five investing blunders I’ve made over the years that rookie and newbie investors should aim to avoid.

Investing mistake 1) Having an overly concentrated portfolio

In order to reduce risk, most investors spread their money around. This is known as diversification: putting your eggs in many baskets. Investing wealth across many different stocks (and varied asset classes) reduces the risk of having spectacular meltdowns. This (blow-ups) has happened to me a couple of times. For example, in 2003, I had a hefty investment in one stock that fell by about three-quarters (-75%). Eventually, my loss on this investment exceeded £100k — much more than I was prepared to lose. Ouch.

2) Buying battered companies

Billionaire investing guru Warren Buffett once wrote, “It’s far better to buy a wonderful company at a fair price than a fair company at a wonderful price”. In the past, I’ve invested in many bombed-out stocks, optimistically hoping they would double or triple in value. Alas, these ailing businesses often got sicker, sending their share prices even lower. Today, I aim to invest in great, market-leading firms with reasonably priced shares. It’s safer for me.

3) Over-trading

In my early years of investing, I used to buy and sell shares very frequently. Indeed, I rarely held onto my shareholdings for long before moving on. In short, I was impatient, flipping stocks for quick gains. But this over-trading greatly increased my dealing costs, eating into my net profits. At this point, I realised I was more like a gambler or trader than a true investor. For example, I once bought into one UK company at 25p a share. A few months later, I sold out for 40p for a 60% profit. Within four or five years, this stock had soared to 250p — a fabled 10-bagger. D’oh.

4) Ignoring dividends

Dividends are regular cash payments made by companies to their shareholders, usually quarterly or half-yearly. Dividends are not guaranteed and can be cut or cancelled at any time. Also, most UK-listed companies don’t pay dividends, though most FTSE 100 companies do. However, investors ignore dividends at their peril. This is because they account for up to half of the long-term returns from investing in UK shares. That’s why every portfolio I build these days includes plenty of passive income in the form of cash dividends. If I choose, I can reinvest this income by buying yet more shares.

Investing mistake 5) Using leverage unwisely

My final investing mistake is one that I would urge all newbies, rookies, and beginners to avoid. It is using leverage — borrowed money or financial derivatives — to boost gains. While leverage can dramatically magnify returns, it does exactly the same for losses. Thus, leverage is a double-edged sword hanging over one’s head. In the worst-case scenario, unwise leverage has wiped out my initial investment and left me owing more. For example, I once bought a block of shares using a 40% deposit and borrowing the other 60% on margin. When the share price crashed, I lost all my investment, plus I owed my broker another £40k. Whoops!

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

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

Is 50 too old to start buying shares?

Christopher Ruane explains why 'better late than never' is key to his thinking about whether 50's too old to start…

Read more »

Two male friends are out in Tynemouth, North East UK. They are walking on a sidewalk and pushing their baby sons in strollers. They are wearing warm clothing.
Investing Articles

Here’s what £150 a month in a Junior ISA could be worth by 2045…

You might be surprised to learn by how large a Junior ISA portfolio could become inside 20 years from modest…

Read more »

Investing Articles

This red hot equity fund in my SIPP returned 12.6% in the first 2 months of 2026

This global equity fund is delivering huge returns for Edward Sheldon’s SIPP in 2026, despite all the risks and uncertainty…

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

Want to retire richer? Here’s Warren Buffett’s golden rule to build wealth

If you want to build wealth for a richer retirement, then following Warren Buffett’s golden rule might be the best…

Read more »

Black woman using smartphone at home, watching stock charts.
Investing Articles

Get ready for stock market volatility…

As conflict in the Middle East makes share prices fluctuate, what strategies can investors use to try and find opportunities…

Read more »

British Isles on nautical map
Investing Articles

Why the FTSE 100 fell almost 5% this week

Declines in mining shares dragged the FTSE 100 down after a strong start to the year. Is the pullback an…

Read more »

Middle aged businesswoman using laptop while working from home
Investing Articles

How much do you need to invest in US stocks to earn a £2,000 monthly passive income?

Is it possible to target several thousand pounds of passive income each month by buying US growth stocks? Absolutely –…

Read more »

A mature woman help a senior woman out of a car as she takes her to the shops.
Investing Articles

How big does your ISA need to be to earn £1,000 a month in passive income?

Andrew Mackie explains how a long-term ISA strategy can help investors build a chunky £12,000 passive income in less than…

Read more »