3 critical investment mistakes I want to avoid in 2019

With Brexit just around the corner, the possibility of making investment mistakes is bigger than ever. Here’s my approach to avoiding them.

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.

The best piece of investment advice I’ve ever read comes from the legendary Warren Buffett. It’s his Rule #1: Never Lose Money. In essence, it means focus first on avoiding mistakes — take care of the downside and the upside will take care of itself, you might say.

With Brexit dominating the UK’s political and economic landscape, are there any key mistakes we should specifically avoid in 2019? I think so.

Beware fallen stocks

The FTSE 100 is full of shares trading at lower P/E levels than a decade ago I wouldn’t have thought possible. Am I saying we shouldn’t buy them? No, just that we should avoid buying the wrong ones.

OK smartypants, I hear you saying, how do we know which are the wrong ones? I can’t know, but I think there’s a key precaution we can take. Many are depressed purely because of Brexit worries and the companies are fine, but there are shares that genuinely deserve to be down in the dumps.

Take Kier Group. It’s crashed because of problems with the company itself. But including it in a ‘fallen stocks’ portfolio just because it’s down would surely be a mistake. When markets are down, we need to be especially careful to distinguish between stocks hit by general macro issues and those with genuine problems of their own.

Brexit timing

I’ve been asked how to time share purchases to make the best of, and avoid the worst of, Brexit. Buy such-and-such a share now, wait until after 31 October, or will waiting mean we’ve missed our chance to get in at the lowest price?

I say ignore all that and make decisions only on what we know now. If, after examining a company’s fundamental business and valuation, I think it represents a bargain now, it goes on my buy list or my watch list and, if not, it doesn’t. That examination obviously includes my estimates of how various Brexit results might affect a share. But any buy decision I make will be “buy now”, not “buy in November”, or whatever.

I have a reasonable sum to invest that I’ve liberated from an old company pension fund and moved to a SIPP, and I’m aware that we could be facing various economic outcomes over the next few months. I’ll probably spread my purchases over the next 12 months — but I’d do the same with any significant investment amount.

Don’t be too greedy

To get back to Warren Buffett, one of his most famous quotes is: “Be fearful when others are greedy and greedy when others are fearful.” So when stocks we like are pushed down to silly low valuations due to fear, should fill our boots with as much as we can afford to buy?

I just don’t have a Buffett level of confidence, and I doubt many other private investors do either. Yes, I can see stocks I think are seriously undervalued. But no, I’m not going for any big “bet the farm” investments, because even with my reasonably long experience, I think that would be reckless.

I take the core of Buffett’s advice to heart, but I’ll be making modest investments across a diversity of stocks.

Alan Oscroft has no position in any of the shares mentioned. The Motley Fool UK has no position in any of the shares mentioned. 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

Investing Articles

Prediction: I think these FTSE 100 shares can outperform in 2026

All businesses go through challenges. But Stephen Wright thinks two FTSE 100 shares that have faltered in 2025 could outperform…

Read more »

pensive bearded business man sitting on chair looking out of the window
Dividend Shares

Prediction: 2026 will be the FTSE 100’s worst year since 2020

The FTSE 100 had a brilliant 2026, easily beating the US S&P 500 index. But after four years of good…

Read more »

Portrait of elderly man wearing white denim shirt and glasses looking up with hand on chin. Thoughtful senior entrepreneur, studio shot against grey background.
Dividend Shares

Prediction: the Lloyds share price could hit £1.25 in 2026

The Lloyds share price has had a splendid 2025 and is inching closer to the elusive £1 mark. But what…

Read more »

Long-term vs short-term investing concept on a staircase
Investing Articles

Here’s how much you need in an ISA of UK stocks to target £2,700 in monthly dividend income

To demonstrate the benefits of investing in dividend-paying UK stocks, Mark Hartley calculates how much to put in an ISA…

Read more »

photo of Union Jack flags bunting in local street party
Investing Articles

Is the FTSE 250 set for a rip-roaring comeback in 2026?

With the FTSE 250 index trading very cheaply, Ben McPoland reckons this market-leading tech stock's worthy of attention in 2026.

Read more »

Young Caucasian man making doubtful face at camera
Dividend Shares

Will the Diageo share price crash again in 2026?

The Diageo share price has crashed 35.6% over one year, making it one of the FTSE 100's worst performers in…

Read more »

Investing Articles

Is Alphabet still one of the best shares to buy heading into 2026?

The best time to buy shares is when other investors are seeing risks. Is that the case with Google’s parent…

Read more »

Investing Articles

Could the Barclays share price be the FTSE 100’s big winner in 2026?

With OpenAI and SpaceX considering listing on the stock market, could investment banking revenues push the Barclays share price higher…

Read more »