Should I sell my FTSE 100 shares and bank profits?

‘Buy low and sell high’ goes the old investing motto. So should I sell my FTSE 100 shares and cash in after the index set a new record high?

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.

Close-up of British bank notes

Image source: Getty Images

London’s blue-chip index broke its all-time high last week, nudging past the previous record of 7,903.5 set in May 2018. In a matter of weeks the Footsie has now quadrupled its 0.9% gain for the whole of last year. Nearly half my overall portfolio is invested in the index. So, should I follow the ‘buy low, sell high’ mantra and cash in my FTSE 100 shares while the going is good?

Is the FTSE 100 now overpriced?

The first thing that might lead me to sell my shares (or at least some of them) is if the UK market became as overvalued as the US market did 18 months ago. There, valuations became irrelevant for software and meme stocks.

For me, a symbol of the speculative excess was space tourism firm Virgin Galactic, which was valued at over $15bn in the summer of 2021. That was despite it generating next to nothing in revenue and nowhere close to even starting commercial operations.

There were dozens of similar examples, before the sharp pin of rising interest rates popped the bubble. Virgin Galactic stock has descended 90% since 2021.

However, I don’t really see anything like that at the moment in the FTSE 100. The index itself seems fairly valued, with a market price-to-earnings (P/E) ratio of 14.2. That’s slightly below its historic average, even after its recent rise.

An international index

If the revenue of the FTSE 100 was derived mainly from the UK, then I’d be cautious with the index trading near an all-time high. That’s because the outlook for the UK economy still isn’t great, despite the Bank of England now forecasting a milder recession than previously feared.

However, approximately 75% of FTSE 100 firms’ revenues come from outside the UK, making the index’s composition truly multinational. So with China reopening and global inflation seeming to cool, I think it makes perfect sense to see the index doing well.

Indeed, I wouldn’t be surprised at all to see it reach new highs over the coming months.

Buy low, sell high?

Charlie Munger famously said that the first rule of compounding is to never interrupt it unnecessarily. And because FTSE 100 dividend payers such as Legal & General and National Grid form an important part of my long-term compounding strategy, I certainly won’t be selling them.

More generally, I don’t believe anyone can consistently predict market movements. That’s because buying low and selling high is a very difficult thing to actually do in real life. Share prices fluctuate every day, so unless I have a crystal ball, it’s impossible to know where prices will head next.

Plus, I’d have to be right twice. I’d have to time when to sell. Then I’d have to correctly judge a near-bottom market point to buy back in. Compounding this difficulty is the fact that the market’s biggest rises happen on a small number of days in any given year. Therefore, if I missed out on one or two of these lucrative days, I’d sabotage my own performance.

To me, the solution is simple. I just stay invested regardless of market fluctuations. This way I don’t have to worry about timing the market, and can take advantage of the power of compounding over time.

Ben McPoland has positions in Legal & General Group Plc and National Grid Plc. 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

Artillery rocket system aimed to the sky and soldiers at sunset.
Investing Articles

£7,500 invested in BAE Systems shares 10 days ago is now worth…

Why have BAE Systems shares experienced a sudden double-digit pullback? And does this present a buying opportunity for my portfolio?

Read more »

Picture of an easyJet plane taking off.
Investing Articles

£10,000 invested in easyJet shares 4 weeks ago is now worth…

It's been a crazy month for easyJet shares. Here's what would have happened to an investor's £10,000 stake put to…

Read more »

CEO Mark Zuckerberg at F8 2019 event
Investing Articles

Down 31%, is this a rare chance to buy Meta stock for my ISA cheaply?

After rising to near $800 in 2025, Meta stock has pulled back to around $550. Edward Sheldon looks at whether…

Read more »

Santa Clara offices of NVIDIA
Investing Articles

18% off its peak, is Nvidia stock now attractively priced?

Nvidia stock has given up almost a fifth of the price it commanded at its peak over the past year.…

Read more »

Aston Martin DBX - rear pic of trunk
Investing Articles

The Aston Martin share price destruction helps illustrate 5 common investing mistakes!

The Aston Martin share price has been a disaster for investors. Christopher Ruane highlights a handful of lessons we can…

Read more »

DIVIDEND YIELD text written on a notebook with chart
Dividend Shares

How this stock market correction can help boost a second income by 25%

Jon Smith explains how rising dividend yields across some existing income shares can be seen as an opportunity to grow…

Read more »

Middle-aged Caucasian woman deep in thought while looking out of the window
Investing Articles

Considering a SIPP? Today’s market could provide an excellent opportunity to start

Mark Hartley breaks down the benefits of using a SIPP for retirement, and how current market conditions could offer a…

Read more »

Calendar showing the date of 5th April on desk in a house
Investing Articles

Looking for last-minute ISA ideas? Check out these UK stocks before April 3

Easter bank holidays mean the deadline to put cash into a Stocks and Shares ISA might be closer than UK…

Read more »