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.

This is the FTSE 100’s worst-performing share over a year. I’m happy to own it!

This popular stock is the FTSE 100’s worst-performing share over 12 months. It’s crashed by a sixth (16.6%). Why do I keep buying it? Here’s the answer!

A GlaxoSmithKline scientist uses a microscope

Image: GlaxoSmithKline

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 past year has been pretty good for the FTSE 100 index. As I write, the Footsie stands at 6,919.88 points. On 14 April 2020, it closed at 5,791.30, hit by surging Covid-19 infections. Thus, the index is up almost 1130 points in 12 months — almost a fifth (19.5%). Of course, as a broad market index, the FTSE 100 tells us nothing about individual share successes and failures. Alas, my largest shareholding is the FTSE 100’s worst performer over the past year.

The FTSE 100 rebounds

As panic over Covid-19 gripped markets, global stock prices collapsed last spring. By 23 March, the FTSE 100 had plunged to a closing low of 4,993.89. However, thanks to massive monetary support from central banks and fiscal support from governments, optimism soon returned. Share prices soared, with this confidence continuing into this year. In 2021, the Footsie has already added almost 460 points (7.1%).

XXX

Over the past year, there have been huge variances in share performances within the FTSE 100. Good news: of the 101 stocks in the Footsie, no fewer than 89 have risen in value over 12 months. These uplifts range from a tiny 0.1% to an impressive 138.6%. Eight of these winning stocks have doubled or better since 14 April 2020. The average gain among these 89 winners is a tidy 45.5% (more than double the 19.5% gain of the wider index).

This is the Footsie’s biggest loser

At the other end of the scale lie 11 losers: the FTSE 100 shares that lost value over the past year. These losses range from just 0.5% to 16.6%, with the average loss coming to 7.4%. But these 11 losers include some real heavyweights, including a global bank, two giant oil companies, and a major pharmaceutical firm. Now for the bad news: shareholders of GlaxoSmithKline (LSE: GSK) own the FTSE 100’s worst-performing share over the past 12 months. I count myself among their number, as GSK is my biggest individual shareholding. Am I annoyed that the GSK share price has fallen by a sixth in a year? Yes! Am I rushing to sell? No! Here’s why.

I think the GSK share price is too cheap

As a young investor in the 1980s/90s, I would often make snap decisions, many of which backfired. After 35 years, I know to take stock before making considered decisions. So, why aren’t I selling the FTSE 100’s biggest loser today? Because I believe these shares to be undervalued and hence due a future re-rating. Also, having fallen over 30% from their 2020 peak (1,857p on 24 January 2020), I don’t see much more downside.

At the current share price of 1,295p, GSK shares trade on a price-to-earnings ratio of 11.26 with an earnings yield of 8.9%. But GSK is the world’s largest vaccine maker by revenue, so its 2020 earnings were depressed by routine vaccination programmes being abandoned during the pandemic. As Covid-19 recedes, these earnings should recover. Meanwhile, the steady 80p-per-share yearly cash payout equates to a dividend yield of 6.2% (almost double that of the wider FTSE 100).

GSK is undergoing rapid change and I do see some risks. It plans to split into two separate businesses in 2022 (BioPharma and Consumer Healthcare), which might hurt earnings. Also, the dividend is set to fall, which is bad news for income investors. And history suggests such radical corporate restructuring can have mixed results, often leading to worse returns. Nevertheless, while GSK’s stock trades at a big discount to the wider FTSE 100, I’ll keep buying more shares by reinvesting my juicy dividends.

Cliffdarcy owns shares of GlaxoSmithKline. The Motley Fool UK has recommended GlaxoSmithKline. 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 »