We have some exciting news to share! The Motley Fool UK has now become The Twelfth Magpie -- an independent, UK-owned company, led by our long-serving UK management team — Mark Rogers, Chris Nials and Heather Adlington. In practical terms, it’s the same team you know, now fully focused on serving our UK readers and members.

Just as importantly, our approach remains unchanged: long-term, jargon-free, and on your side. This site is our new home, and there will be extra tweaks made across the coming few days as we settle in. So if anything looks a little off, please bear with us!

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.

3 costly investing mistakes to avoid

To become better investors, we first need to recognise where we’re going wrong. Paul Summers offers up three investing mistakes of his own.

Hispanic man using laptop in home office and drinking coffee

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.

Becoming better at anything usually involves needing to reflect on our errors. Stock picking (and holding) is no different. Here are three investing mistakes that have held me back over the years and how I’ve tried to overcome them. 

Mistake #1: Having too little/too much patience

Unless I’m queueing for petrol, I like to think of myself as a patient soul. However, there have been times over my investing journey where I’ve been unable to sit on my hands. This has usually involved snatching at profits ( FTSE 100 stock Halma springs to mind) or selling on a bit of temporary bad news (step forward online casino operator 888). Just to muddy the waters somewhat, I’ve also been too patient at times and waited for a recovery that never arrives. Sometimes it’s better to get out, stay out, and take the loss.

XXX

There’s no perfect solution here. However, simply getting into the habit of reflecting on exactly why I’m wanting to act/not act is a start. Keeping a journal and revisiting my reasons for buying a particular stock also helps. Has a company’s strategy changed? Is this now a better business? If yes, why sell?

Mistake #2: It’s all about the price

The ‘buy low, sell high’ mantra persists because it’s patently good advice. However, investing mistakes arise when I tend to put too much weight into categorising something as ‘cheap’ or ‘expensive’. An expensive stock becomes a bargain if the underlying business grows massively. A cheap share can become cheaper if the underlying business is failing.

Now, let’s not get silly here. I’m not suggesting a stock trading on a P/E of 20 is somehow cheaper than one trading on a P/E of 10. My point is simply to look beyond this basic metric and ask whether the price is fair relative to what I’d be getting for it.

Does the company consistently deliver great returns on capital? Is it unfairly valued compared to sub-standard rivals? Does it have the finances to withstand a stock market crash? If so, I’ve likely found a good business worth paying more for. 

Owners of Fundsmith Equity will know that Terry Smith always puts quality ahead of price when picking stocks. To date, this has enhanced rather than impeded his returns.

Mistake#3: Listening to the noise

It’s remarkably easy to assume that the more information I gather about a stock, the greater the edge I have over my peers.

This tactic isn’t necessarily irrational. Finding a promising company that’s flying under many investors’ radars can sometimes generate incredible returns. Think Argo Blockchain from December 2020 to Feburary 2021. 

That said, any information-grabbing exercise must always consider the quality of the source. Back in the day, for example, I’d pay attention to forums and social media sites like Twitter. There would be the odd useful nugget among the dross, but the signal-to-noise trade-off was invariably poor. 

These days, my approach is far more focused and reflects my limited time. My first port of call is always the London Stock Exchange’s news page. I’ll also listen to podcasts or audiobooks from/about proven investors (William Green’s ‘Richer, Wiser, Happier’ is highly recommended).

Again, this won’t guarantee great returns. Even the best are still susceptible to investing mistakes. Nevertheless, standing on the shoulders of identifiable giants rather than unverifiable online personas sounds far less risky.

Paul Summers owns shares in Fundsmith Equity. The Motley Fool UK has recommended Halma. 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

Friends and sisters exploring the outdoors together in Cornwall. They are standing with their arms around each other at the coast.
Investing Articles

£503 buys 14 shares in this FTSE 250 stock that returned 23.9% annually for the last 15 years

This FTSE 250 stock has averaged a huge return for 15 years. At today's price, £503 buys 14 shares. But…

Read more »

Black woman using loudspeaker to be heard
Investing Articles

£1,000 buys 25 shares in this FTSE 100 stock that’s returned 29.2% annually for the last 10 years

This FTSE 100 mining stock has returned close to 30% a year for a decade. At 3,995p, £1,000 buys 25…

Read more »

Female student sitting at the steps and using laptop
Investing Articles

Down 47%, is this growth stock finally worth buying in May?

With a £288m order book and a hidden pipeline of defence and nuclear contracts, is this growth stock now too…

Read more »

House models and one with REIT - standing for real estate investment trust - written on it.
Investing Articles

2 REITs yielding 7%+ to consider for passive income in 2026

A REIT backed by the NHS and another backed by Tesco and Sainsbury's with both yielding 7%+. Here's why I'm…

Read more »

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

Just 97 shares of this UK dividend stock generate £238 in passive income

A 5.7% yield, £238 in passive income from just 97 shares, and one of the most divisive dividend stocks on…

Read more »

ISA coins
Investing Articles

£10,000 in an ISA generates a second income of…

The London Stock Exchange is home to some of the world's most generous dividends. But how big a second income…

Read more »

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

Expert recommendations: 2 top income stocks yielding 7%+!

With yields of 7.2% and 7.8% respectively, these two income stocks are catching the eyes of institutional analysts. Should investors…

Read more »

Illustration of flames over a black background
Investing Articles

3 top income-focused stocks to buy in May 2026, according to experts

Looking for a stock to buy for income in May 2026? Experts have flagged these three UK dividend shares as…

Read more »