The FTSE 100: Four Decades of Britain's Blue Chip Barometer
By Boring Money
13 Jan, 2026
What is the FTSE 100?
The FTSE 100 is the UK's most famous stock market index, tracking the 100 largest companies listed on the London Stock Exchange by market capitalisation. It launched on January 3, 1984, with a starting level of 1,000 points and has since become the primary indicator of the UK stock market's performance.
When was the FTSE 100 created?
The FTSE 100 was created on 3 January 1984 by the London Stock Exchange. It was initially called the SE 100 (Stock Exchange 100), but it was renamed within weeks to include the Financial Times, becoming the Financial Times Stock Exchange 100 Index – now universally known as the FTSE 100 or "Footsie".
Why was the FTSE 100 needed?
Before 1984, the UK's primary stock market index was the FT 30, which had been running since 1935. The FT 30 tracked just 30 companies chosen by Financial Times editors and was only calculated once an hour.
By the early 1980s, this was no longer fit for purpose. Share trading was becoming computerised, and there was growing demand for derivatives like futures and options.
With the launch of traded options, London needed an index that was continuously updated during market hours and more representative of the London stock market.
The FTSE 100 updated every 60 seconds when it launched – revolutionary for 1984. By 1995 it was updating every 15 seconds, and by 1997 it moved to real-time updates.
How did the Big Bang affect the FTSE 100?
The FTSE 100's timing was perfect. Just two years after its launch came the Big Bang of 1986 – Margaret Thatcher's sweeping deregulation of financial markets. This coincided with major privatisations of state-owned companies.
British Telecom's privatisation in December 1984 was particularly significant, generating enormous publicity with around two million UK citizens applying to buy shares. On the first day of trading, BT shares rose by a third from their offer price of 130p.
Other high-profile privatisations followed: British Gas, British Aerospace, British Airways, and British Petroleum. These newly privatised giants became FTSE 100 constituents, helping the index become Britain's go-to market indicator.
What happened during Black Monday 1987?
In October 1987, the FTSE 100 experienced its most dramatic crash. Black Monday saw the index fall around 23% over two days, with one single day recording –12.22% – still the index's worst daily return on record.
Despite the crash, trading volumes on FTSE futures contracts surged dramatically, reaching several times the normal daily average. The index recovered and continued climbing through the 1990s, topping 7,000 in early 2000.
Which original FTSE 100 companies are still listed?
Of the 100 companies that made up the first FTSE 100 in 1984, around 26 original members remain on the index today. Survivors include Barclays, Marks & Spencer, Prudential, Rio Tinto and Unilever – though some have dropped out and returned over the years.
Many have different stories. Boots became the first FTSE 100 member bought by a private equity firm in 2007. Midland Bank was taken over by HSBC in 1992. Only three of the original 100 have gone bust entirely: British & Commonwealth, Ferranti, and MFI.
How has the FTSE 100 performed during crises?
2008 Financial Crisis: The index fell 31% – its worst annual performance since launch. Banks were particularly hard hit, accounting for 12.67% of the FTSE 100 at the time. The index regained losses over the following two years.
2016 Brexit Vote: The FTSE 100 fell sharply in early trading on 23 June 2016 after the referendum result. However, the subsequent fall in the pound's value boosted the index's international companies.
2020 Coronavirus Pandemic: Another swift decline followed by rapid recovery after massive government intervention.
Is the FTSE 100 really a British index?
Here's something that surprises many people: around three-quarters of FTSE 100 constituent earnings come from non-UK activities. The index is dominated by international companies that happen to be listed in London.
The FTSE 250 – tracking the next 250 largest companies – is considered a better indicator of the UK economy, as it contains more domestically focused businesses.
What are the current challenges facing the FTSE 100?
In 2024, the London market saw its most delistings since the 2008 financial crisis. Companies cited higher valuations available by switching to the New York Stock Exchange. Major FTSE 100 members Ashtead Group, CRH, and Flutter – representing almost £120 billion in market capitalisation – all moved to American listings.
How high is the FTSE 100 now?
The FTSE 100 recently broke through 10,000 points for the first time, having started at 1,000 points in 1984. However, its real story isn't just about rising numbers – it's a chronicle of how Britain's economy and business landscape have transformed from a largely domestic focus to a collection of global giants.
Who maintains the FTSE 100?
The index is maintained by FTSE Russell, a wholly owned subsidiary of London Stock Exchange Group. FTSE Russell originated as a joint venture between the Financial Times and the London Stock Exchange.
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[1] FTSE 100 Index, Wikipedia (January 2026)
[2] "The FTSE 100 Index: The UK's best-known equity index turns forty", LSEG (2024)
[3]"History of the FTSE 100", City Index (May 2023)
[4]"FTSE 100 Index Insights, FTSE Russell (2024)
[5]"FTSE 100: 40 years of ups and downs at the top of British business", Raconteur (April 2024)
[6]"The FTSE 100 survivors", ii (2019)
