5 things to understand before you start investing

Christopher Ruane lays out a handful of principles he would bear in mind if he was to start investing for the first time today.

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.

Couple working from home while daughter watches video on smartphone with headphones on

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.

It can be exciting thinking about the possible returns of investing in the stock market. That helps explain why some people rush into it and start investing before they really understand what they are doing.

If I was going to begin investing for the first time, here are five things I would like to know.

1. Costs matter

Some investment trusts charge an annual management fee, often a low-single-digit percentage number. Buying or selling any shares usually also attracts fees. They can also sound low on paper, again in the single-digit percentage range.

But a few percentage points here and a couple of percentage points there can soon add up. The more one trades, the sooner such costs are likely to add up.

I would begin by comparing different share-dealing accounts and Stocks and Shares ISAa to see which one looked most appropriate for my needs.

2. The future is not the past

Past performance can be very helpful when investing. For example, knowing how a business did in the past can help me decide whether its business model looks proven and what sort of seasonality it has.

But past performance is not necessarily a guide to what comes next, even for a proven business with a long history. Fortunes have been lost by investors sinking money into fallen giants, only to see them keep on falling.

3. Chasing yield is a fool’s errand

The dividend yield is the amount one receives each year as dividends as a percentage of the cost of the shares.

For example, Diversified Energy currently has a yield of 16%. If that is sustained, spending £100 on Diversified shares today ought to earn me £16 in dividends annually. Even at a time of high interest rates, that sort of yield grabs my attention.

But dividends are never guaranteed. A common mistake when people start investing is simply to look at yields, without understanding the business concerned. A high yield alone tells me nothing. Instead, I need to understand the business concerned and judge how able I think it will likely be to maintain its shareholder payout.

4. Diversification is simple but important

Many people have their eye on what they think is an amazing share when they start investing. Anyone who has ever heard someone in a pub drone on about how they almost bought Amazon or Tesla shares before the companies grew huge, will have experienced this first-hand.

While some companies do well, others perform terribly. There are lots of ways to form an opinion on what is likely to happen – but there is no way to know for sure ahead of time.

By spreading my eggs over multiple baskets, I can reduce the risk to my portfolio if one share I choose later performs badly.

5. Stay calm

Investing involves risking one’s money. The twists and turns of the stock market can seem exciting – or nerve-racking.

Investing is ultimately about making money. I think a valuable lesson when one starts investing is always to stay calm and try to avoid emotionally driven decision-making.

As legendary investor Warren Buffett says: “When forced to choose, I will not trade even a night’s sleep for the chance of extra profits.”

John Mackey, former CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool’s board of directors. C Ruane has no position in any of the shares mentioned. The Motley Fool UK has recommended Amazon.com and Tesla. 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

Rolls-Royce's Pearl 10X engine series
Investing Articles

£10,000 invested in Rolls-Royce shares 5 Christmases ago is now worth…

James Beard reflects on the post-pandemic Rolls-Royce share price rally and whether the group could become the UK’s most valuable…

Read more »

Investing Articles

Will Nvidia shares continue their epic run into 2026 and beyond?

Nvidia shares have an aura of invincibility as an AI boom continues to benefit the chipmaker. Can anything stop the…

Read more »

Investing Articles

Can Babcock’s and BAE Systems’ shares blast off again in 2026?

The defence sector has been going great guns in 2025, so Harvey Jones looks at whether BAE systems’ and Babcock’s…

Read more »

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

£10,000 invested in Lloyds shares at the beginning of 2025 is now worth…

It's been a banner year for Lloyds shares! Here is what a £10,000 stake would have returned over the course…

Read more »

Frustrated young white male looking disconsolate while sat on his sofa holding a beer
Investing Articles

I asked ChatGPT if I was an idiot for buying Aston Martin shares and it said…

Investors so caught up with the Christmas spirit might think it's a good idea to buy Aston Martin shares. But…

Read more »

Growth Shares

How high could the Vodafone share price go in 2026?

Jon Smith explains why the Vodafone share price is carrying strong momentum into 2026 and why it could continue to…

Read more »

Content white businesswoman being congratulated by colleagues at her retirement party
Investing Articles

I asked ChatGPT to find 3 shares for a brand new SIPP, and it picked…

Many UK investors will have an ISA or SIPP on their planning lists for 2026, while others seek new additions…

Read more »

Businessman hand stacking money coins with virtual percentage icons
Investing Articles

How high can the Lloyds share price go in 2026?

The Lloyds Bank share price has made some stellar gains in 2025, and some analysts are already forecasting further rises…

Read more »