FTSE 100 Index

The Financial Times Stock Exchange 100 Index, also called the FTSE 100 Index, FTSE 100, FTSE, or, informally, the "Footsie" Template:IPAc-en, is one of the United Kingdom's best-known stock market indices and represents the 100 most highly capitalised blue chips listed on the London Stock Exchange.

History

The index started on 3 January 1984, having been constructed by the London Stock Exchange to better reflect activity on the market. The index would replace the Financial TimesTemplate:' own FT 30 after its public unveiling on 14 February. As late as 10 February, the Stock Exchange referred to the index as 'SE 100', cutting out the Financial Times who had not contributed to its construction. Recognition was ultimately given to the fact that having the FT involved in the official launch possessed value.

The new index allowed the Stock Exchange's own London Traded Options Market (LTOM) to launch an options contract derived from the FTSE's real-time data in May 1984, while competitors LIFFE were quick to coincide their launch of the futures contract.

Usage of the index grew, although the tradeable index contracts struggled to gain traction: annual volume on the FTSE futures contract fell short of 89,000 in 1985, pale in comparison to the 15 million lots traded on the S&P 500 index contract. By 1986, Margaret Thatcher's sweeping financial deregulation and high profile privatisations of index members British Telecom, British Gas, and British Aerospace had culminated in the Big Bang. The combination of a new index, major privatisations, LIFFE tradable derivatives, and promotion by the Financial Times led to the FTSE 100 becoming the most widely used indicator of whether the UK stock market was rising or falling.

In 1987, privatisations continued with British Airways and British Petroleum. The latter concluded on the same day as Black Monday, a crash in which the index fell 21.73% in two days; one of those days is still the index's worst single-day return, –12.22%. While the index was in freefall trading volume of the futures contract hit a record high of 9,111 contracts in a single day. By comparison the volume in the week preceding the crash averaged 2,400 contracts per day.

By the spring of 1992 LTOM was sold to LIFFE for a nominal sum, consolidating derivatives of the FTSE 100 index into one exchange. Trading of these instruments remained solely in the institutional domain since the significant investment required to deliver electronic trading limited retail access at the time. Nonetheless annual volumes for 1992 in FTSE futures and options contracts hit a new high of 2.6 million and 2.2 million respectively. In the autumn the Bank of England directed by HM Treasury under John Major's government failed to prop up sterling to maintain the European Exchange Rate Mechanism. A swift devaluation of sterling on Black Wednesday and exit from the ERM benefitted the globally trading FTSE index constituents enormously as exports became cheaper overnight. Closing on the 15 September 1992 at 2,370.0 the index would almost triple by the end of the decade hitting a high of 6,930.2 on 30 December 1999.

In 2024, there were the most delistings from the London market since the 2008 financial crisis, with companies citing higher valuations and cheaper costs available by switching to NYSE. Among them Ashtead Group, CRH, and Flutter represented almost £120 billion in FTSE 100 market capitalisation. Takeovers from private equity further reduced the available pool of companies that could be drawn on to populate the index, with Hargreaves Lansdown also set to delist. Across the entire exchange there were five delistings for every new issue, with speculation at the close of the year around the future of index stalwarts British American Tobacco, Rio Tinto, and Shell.

Description

The index has trading symbol UKX and is maintained by FTSE Russell, a wholly owned subsidiary of London Stock Exchange Group, which originated as a joint venture between the Financial Times and the London Stock Exchange. It is calculated in real time and published every second when the market is open.

The FTSE 100 broadly consists of the largest 100 qualifying UK companies by full market value. The total market value of a company is calculated by multiplying the share price of the company by the total number of shares they have issued. However, many of these are internationally focused companies: therefore the index's movements are a fairly weak indicator of how the UK economy is faring and are significantly affected by the exchange rates of the pound sterling. A better indication of the UK economy is the FTSE 250 Index, as it contains a smaller proportion of international companies.

Even though the FTSE All-Share Index is more comprehensive, the FTSE 100 is by far the most widely used UK stock market indicator. Other related indices are the FTSE 250 Index (which includes the next largest 250 companies after the FTSE 100), the FTSE 350 Index (which is the aggregation of the FTSE 100 and 250), FTSE SmallCap Index and the FTSE Fledgling Index. The FTSE All-Share aggregates the FTSE 100, FTSE 250 and FTSE SmallCap.

The index consists of 18 ICB Supersectors, four of which had a market capitalisation exceeding £200 billion since 30 September 2025Template:Dated maintenance category (articles). These are Banks, Health Care, Industrial Goods and Services and Energy, which together account for approximately 51% of the index's capitalisation. On the same date, there were five companies with a market cap exceeding £100 billion: AstraZeneca, Shell, HSBC, Unilever and Rolls-Royce, which together accounted for approximately 31% of the market cap.

Each calendar quarter, the FTSE's constituents are reviewed and some companies exit or enter the index, resulting in irregular trading volume and price changes as market participants rebalance their portfolios.

Weighting

In the FTSE indices, share prices are weighted by free-float capitalisation, so that the larger companies, with more of their stock "floating", make more of a difference to the index than smaller companies. The basic formula for these indices is:

$\begin{array}{rl}\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{v}\mathrm{a}\mathrm{l}\mathrm{u}\mathrm{e}& =\frac{\mathrm{T}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}\mathrm{m}\mathrm{a}\mathrm{r}\mathrm{k}\mathrm{e}\mathrm{t}\mathrm{v}\mathrm{a}\mathrm{l}\mathrm{u}\mathrm{e}}{\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{d}\mathrm{i}\mathrm{v}\mathrm{i}\mathrm{s}\mathrm{o}\mathrm{r}}\end{array}$

expanded to,

$\begin{array}{rl}\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{v}\mathrm{a}\mathrm{l}\mathrm{u}\mathrm{e}& =\frac{\sum _{i=1}^n({\mathrm{P}\mathrm{r}\mathrm{i}\mathrm{c}\mathrm{e}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{t}\mathrm{o}\mathrm{c}\mathrm{k}}_{i,t}\times {\mathrm{N}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r}\mathrm{o}\mathrm{f}\mathrm{s}\mathrm{h}\mathrm{a}\mathrm{r}\mathrm{e}\mathrm{s}}_{i,t}\times {\mathrm{F}\mathrm{r}\mathrm{e}\mathrm{e}\mathrm{f}\mathrm{l}\mathrm{o}\mathrm{a}\mathrm{t}\mathrm{f}\mathrm{a}\mathrm{c}\mathrm{t}\mathrm{o}\mathrm{r}}_{i,t})}{\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{d}\mathrm{i}\mathrm{v}\mathrm{i}\mathrm{s}\mathrm{o}\mathrm{r}}\end{array}$

where the sum of the products of the $price$, $shares$, and $FFF$ for each component beginning at $i=1$ through to, usually, $n=100$ at time $t$ are divided by the $indexdivisor$ to give the $indexvalue$.

The free float factor represents the percentage of all issued shares that are readily available for trading, rounded up to the nearest multiple of 5%. The free-float capitalisation of a company is its market capitalisation multiplied by its free float adjustment factor. It therefore does not include restricted stocks, such as those held by company insiders.

It follows that the $indexdivisor$ at any chosen time, when there are no changes, is derived by rearranging the basic formula to give:

$\begin{array}{rl}\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{d}\mathrm{i}\mathrm{v}\mathrm{i}\mathrm{s}\mathrm{o}\mathrm{r}& =\frac{\mathrm{T}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}\mathrm{m}\mathrm{a}\mathrm{r}\mathrm{k}\mathrm{e}\mathrm{t}\mathrm{v}\mathrm{a}\mathrm{l}\mathrm{u}\mathrm{e}}{\mathrm{I}\mathrm{n}\mathrm{d}\mathrm{e}\mathrm{x}\mathrm{v}\mathrm{a}\mathrm{l}\mathrm{u}\mathrm{e}}\end{array}$

However, as with any price index the FTSE 100 Index is always changing, whether by corporate action or constituent change. In order to maintain a true reflection of market price movements the $indexdivisor$ is adjusted to mitigate any effect these changes have on the index value.

FTSE Russell employs the index formula developed by Hermann Paasche for adjusting the $indexdivisor$ for values preceding a corporate action and uses the change in the $indexvalue$ arising from the adjusted divisor to calculate the new value on the day of the corporate action.

The Paasche formula is given as:

$\begin{array}{rl}{\mathrm{I}}_t^{Paas}& =\frac{\sum _{i=1}^n{\mathrm{P}}_{i,t}{\mathrm{Q}}_{i,t}}{\sum _{i=1}^n{\mathrm{P}}_{i,0}{\mathrm{Q}}_{i,t}}\end{array}$

where,

${\mathrm{I}}_t^{Paas}$	= Paasche Index
${\mathrm{P}}_{i,t}$	= price at start of day $t$ for constituent $i$ after adjustments for action or event
${\mathrm{P}}_{i,0}$	= price of constituent $i$ on the starting day of calculating the index
${\mathrm{Q}}_{i,t}$	= number of shares included in the index for constituent $i$ at the start of day $t$

Since the index is always based on the prior value and not the fixed base value, a Chained Paasche Index is used to chain each new value with the last continuously. This is given by the formula:

$\begin{array}{rl}{\mathrm{I}}_t^{Paas}& ={\mathrm{I}}_{t-1}^{Paas}\frac{\sum _{i=1}^n{\mathrm{P}}_{i,t}{\mathrm{Q}}_{i,t}}{\sum _{i=1}^n{\mathrm{P}}_{i,t-1}{\mathrm{Q}}_{i,t}}\end{array}$

In isolation, the Chained Paasche Index will not adjust the prior closing value, resulting in an abnormal price difference. FTSE Russell utilises a $priceadjustmentfactor$ to give continuity, given by the formula:

$\begin{array}{rl}{\mathrm{I}}_t^{Paas}& ={\mathrm{I}}_{t-1}^{Paas}\frac{\sum _{i=1}^n{\mathrm{P}}_{i,t}{\mathrm{Q}}_{i,t}}{\sum _{i=1}^n{\mathrm{P}}_{i,t-1}{\mathrm{Q}}_{i,t}{\mathrm{P}\mathrm{A}\mathrm{F}}_{i,t}}\end{array}$

So the $indexvalue$ or ${\mathrm{I}}_t^{Paas}$ is equal to the product of the previous $indexvalue$ or ${\mathrm{I}}_{t-1}^{Paas}$ at time $t-1$, one period before, and the sum of the products of constituents $i$ through $n$'s price $P$ and quantity $Q$ at time $t$ divided by the sum of the products of constituents $i$ through $n$'s price $P$ at time $t-1$ and their quantity $Q$ and their $priceadjustmentfactor$ at time $t$.

Futures contracts

The benchmark FTSE 100 futures contracts are traded on the ICE Futures Europe (ICEU) exchange, formerly the London International Financial Futures Exchange (LIFFE). The value of each contract is 10 GBP × index points and is specified as:

FTSE 100 (Z) contract specifications

Contract size	10 GBP × index points
Exchange	ICEU
Sector	Index
Contract Symbol	Z
Tick size	0.5
Tick value	5 GBP
Basis Point Value	10
Denomination	GBP
Decimal places	1

On the last trading day of each quarterly futures contract, the settlement price is determined using an intraday auction of all FTSE 100 stocks on the London Stock Exchange, starting at 10:15.

Record values

The index has reached the following record values:

Category	All-time highs
Closing	9,911.42	12 November 2025
Intraday	9,930.09	12 November 2025

The index began on 3 January 1984 at the base level of 1,000. The highest closing value of 9,911.42 was reached on 12 November 2025 and the highest intraday value of 9,930.09 was reached on the 12 November 2025.

Annual returns

The following table shows the annual development of the calculation of the FT 30 Index from 1969 to 1983, and the FTSE 100 since 1984.

Year	Closing level	Change in index
		(points)	(%)
1969	313.16
1970	289.61	−23.55	−7.52
1971	411.03	121.42	41.93
1972	463.72	52.69	12.82
1973	318.30	−145.42	−31.36
1974	142.17	−176.13	−55.33
1975	335.98	193.81	136.32
1976	322.98	−13.00	−3.87
1977	455.96	132.98	41.17
1978	468.06	12.10	2.65
1979	488.40	20.34	4.35
1980	620.60	132.20	27.07
1981	665.50	44.90	7.23
1982	812.37	146.87	22.07
1983	1,000.00	187.63	23.10
1984	1,232.20	232.20	23.22
1985	1,412.60	180.40	14.64
1986	1,679.00	266.40	18.86
1987	1,712.70	33.70	2.01
1988	1,793.10	80.40	4.69
1989	2,422.70	629.60	35.11
1990	2,143.50	−279.20	−11.52
1991	2,493.10	349.60	16.31
1992	2,846.50	353.40	14.18
1993	3,418.40	571.90	20.09
1994	3,065.50	−352.90	−10.32
1995	3,689.30	623.80	20.35
1996	4,118.50	429.20	11.63
1997	5,135.50	1,017.00	24.69
1998	5,882.60	747.10	14.55
1999	6,930.20	1,047.60	17.81
2000	6,222.46	−707.74	−10.21
2001	5,217.35	−1,005.11	−16.15
2002	3,940.36	−1,276.99	−24.48
2003	4,476.87	536.49	13.62
2004	4,814.30	337.57	7.54
2005	5,618.76	804.46	16.71
2006	6,220.81	602.05	10.71
2007	6,456.91	236.10	3.80
2008	4,434.17	−2,022.74	−31.33
2009	5,412.88	978.71	22.07
2010	5,899.94	487.06	9.00
2011	5,572.28	−327.66	−5.55
2012	5,897.81	325.53	5.84
2013	6,749.09	851.29	14.43
2014	6,566.09	−183.00	−2.71
2015	6,274.05	−292.04	−4.45
2016	7,142.83	868.78	13.85
2017	7,687.77	544.94	7.63
2018	6,728.13	−959.64	−12.48
2019	7,542.44	814.31	12.10
2020	6,460.52	−1,081.92	−14.34
2021	7,384.54	924.02	14.30
2022	7,451.74	67.20	0.91
2023	7,733.24	281.50	3.78
2024	8,173.02	439.76	5.69

Constituents

The following table lists the FTSE 100 companies after the changes on 19 December 2025.

Company	Ticker	FTSE industry classification benchmark sector
3i	III	Financial services
Admiral Group	ADM	Insurance
Airtel Africa	AAF	Telecommunications services
Alliance Witan	ALW	Investment Trusts
Anglo American plc	AAL	Mining
Antofagasta plc	ANTO	Mining
Ashtead Group	AHT	Support services
Associated British Foods	ABF	Food & tobacco
AstraZeneca	AZN	Pharmaceuticals & biotechnology
Auto Trader Group	AUTO	Media
Aviva	AV	Life insurance
Babcock International	BAB	Aerospace & defence
BAE Systems	BA	Aerospace & defence
Barclays	BARC	Banks
Barratt Redrow	BTRW	Household goods & home construction
Beazley	BEZ	Insurance
Berkeley Group Holdings	BKG	Household goods & home construction
BP	BP	Oil & gas producers
British American Tobacco	BATS	Tobacco
British Land	BLND	Real estate
BT Group	BT-A	Telecommunications services
Bunzl	BNZL	Support services
Burberry Group	BRBY	Personal goods
Centrica	CNA	Multiline utilities
Coca-Cola Europacific Partners	CCEP	Beverages
Coca-Cola HBC	CCH	Beverages
Compass Group	CPG	Support services
Convatec	CTEC	Health care equipment & supplies
Croda International	CRDA	Chemicals
DCC plc	DCC	Support services
Diageo	DGE	Beverages
Diploma	DPLM	Industrial Support services
Endeavour Mining	EDV	Precious Metals and Mining
Entain	ENT	Travel & leisure
EasyJet	EZJ	Travel & leisure
Experian	EXPN	Support services
F & C Investment Trust	FCIT	Collective investments
Fresnillo plc	FRES	Mining
Games Workshop	GAW	Leisure Goods
Glencore	GLEN	Mining
GSK plc	GSK	Pharmaceuticals & biotechnology
Haleon	HLN	Pharmaceuticals & biotechnology
Halma plc	HLMA	Electronic equipment & parts
Hikma Pharmaceuticals	HIK	Pharmaceuticals & biotechnology
Hiscox	HSX	Non-life Insurance
Howdens Joinery	HWDN	Homebuilding & construction supplies
HSBC	HSBA	Banks
ICG	ICG	Financial services
IHG Hotels & Resorts	IHG	Travel & leisure
IMI	IMI	Industrial engineering
Imperial Brands	IMB	Tobacco
Informa	INF	Media
International Airlines Group	IAG	Travel & leisure
Intertek	ITRK	Support services
JD Sports	JD	General retailers
Kingfisher plc	KGF	Retailers
Land Securities	LAND	Real estate investment trusts
Legal & General	LGEN	Life insurance
Lloyds Banking Group	LLOY	Banks
LondonMetric Property	LMP	Real Estate Investment Trusts
London Stock Exchange Group	LSEG	Financial services
M&G	MNG	Financial services
Marks & Spencer	MKS	Food & drug retailing
Melrose Industries	MRO	Aerospace & defence
Metlen Energy & Metals	MTLN	Multiline utilities
Mondi	MNDI	Containers & packaging
National Grid plc	NG	Multiline utilities
NatWest Group	NWG	Banks
Next plc	NXT	General retailers
Pearson plc	PSON	Media
Pershing Square Holdings	PSH	Financial services
Persimmon	PSN	Household goods & home construction
Phoenix Group	PHNX	Life insurance
Polar Capital Technology Trust	PCT	Investment trusts
Prudential plc	PRU	Life insurance
Reckitt	RKT	Household goods & home construction
RELX	REL	Media
Rentokil Initial	RTO	Support services
Rightmove	RMV	Media
Rio Tinto	RIO	Mining
Rolls-Royce Holdings	RR	Aerospace & defence
Sage Group	SGE	Software & computer services
Sainsbury's	SBRY	Food & drug retailing
Schroders	SDR	Financial services
Scottish Mortgage Investment Trust	SMT	Collective investments
Segro	SGRO	Real estate investment trusts
Severn Trent	SVT	Multiline utilities
Shell plc	SHEL	Oil & gas producers
Smiths Group	SMIN	General industrials
Smith & Nephew	SN	Health care equipment & supplies
Spirax Group	SPX	Industrial engineering
SSE plc	SSE	Electrical utilities & independent power producers
Standard Chartered	STAN	Banks
St. James's Place	STJ	Financial services
Tesco	TSCO	Food & drug retailing
Unilever	ULVR	Personal goods
United Utilities	UU	Multiline utilities
Vodafone Group	VOD	Mobile telecommunications
Weir Group	WEIR	Industrial goods and services
Whitbread	WTB	Retail hospitality

Past constituents

All changes are due to market capitalisation changes unless noted otherwise.

Source: "FTSE: FTSE 100 Constituent Changes" (PDF; 57.9 KB)

FT 30

The oldest continuous index in the UK is the FT 30, also known as the Financial Times Index or the FT Ordinary Index (FTOI). It was established in 1935 and nowadays is largely obsolete due to its redundancy. It is similar to the Dow Jones Industrial Average, and companies listed are from the industrial and commercial sectors. Financial sector companies and government stocks are excluded.

Of the original constituents, three are currently in the FTSE 100: Tate & Lyle, Imperial Tobacco and Rolls-Royce, although Rolls-Royce has not been continuously listed and Imperial Tobacco was a subsidiary of Hanson for a number of years, and is now renamed as Imperial Brands. Only one of the original FT 30 companies is still in that index: Tate & Lyle (membership is not strictly based on market capitalisation, so this does not mean they are necessarily among the top thirty companies in the FTSE 100). The best performer from the original lineup has been Imperial Tobacco.

See also

Other lists

• List of corporate collapses and scandals, on major bankruptcies historically and worldwide
• List of hedge funds
• List of largest companies by revenue, worldwide
• List of largest companies in the United Kingdom
• List of largest United Kingdom employers, including the public sector
• List of private-equity firms

Stock market lists

• AEX index
• Dow Jones Industrial Average and the DAX 30, equivalent to the FT 30 in the US and Germany
• Financial Times Global 500, the BBC Global 30 and the Fortune Global 500, list the world's largest corporations by market capitalisation
• FTSE 250 and FTSE techMARK 100, a longer FT list, and one for the "new economy"
• List of European stock exchanges
• List of stock exchanges
• List of stock market indices
• S&P 100 and the HDAX, top 100 in the US and top 110 in Germany

External links

• LSEG page for FTSE 100