FTSE 100
Tracks the 100 largest companies listed on the London Stock Exchange by market capitalization.
Operator
FTSE Russell
Launched
1984
Country
United Kingdom
Methodology
Market-capitalization weighted, reviewed quarterly.
How Investors Use This Index
Because a large share of FTSE 100 constituents earn most of their revenue outside the United Kingdom, the index often behaves more like a proxy for global growth and commodity prices than a pure read on the UK's domestic economy — it's not unusual for the index to rise even during periods of sluggish UK growth, or for a weaker British pound to lift the index by boosting the reported value of overseas earnings. This distinguishes it from more domestically weighted UK benchmarks like the FTSE 250.
Major Sectors
Frequently Asked Questions
Does the FTSE 100 reflect the UK economy?
Not closely. Most constituent revenue is earned internationally, so the index tracks global growth and commodity cycles more than domestic UK conditions.
Why does a weaker pound often push the FTSE 100 higher?
Because a large share of constituent earnings are generated in foreign currencies and translate into more pounds when sterling weakens.
How is the FTSE 100 different from the FTSE 250?
The FTSE 100 covers the largest, most internationally-earning companies; the FTSE 250 covers the next tier down and skews more domestically focused.
How often does the FTSE 100 change its constituents?
Quarterly reviews rank companies by market capitalization; those falling out of the top 110 are typically removed, and those rising into the top 90 are typically added.