The Financial Times Stock Exchange 100 Index, also known as the FTSE 100 Index or the Footsie 100, is a share index of the largest 100 listed companies in the UK by market capitalisation and contains some of the biggest companies in the world.
The FTSE 100 index essentially tracks the performance of the share prices of the 100 largest, most actively traded companies on the London Stock Exchange (LSE).
The FTSE 100 began with a base of 1,000 in 1984, replacing the price-weighted FT30 Index.
The index is calculated by weighing all stocks listed on the London Stock Exchange by market capitalisation.
Market capitalisation, often referred to as market cap, is the total value of all outstanding shares in a company.
What are the other UK indices?
Other UK indices include the FTSE 250, FTSE 350, FTSE SmallCap and FTSE All-Share.
FTSE also has three indices for AIM stocks (Alternative Investment Market ) which is the London Stock Exchange’s (LSE’s) international market for small and medium-size growth companies. These include FTSE AIM UK 50, FTSE AIM 100 and FTSE AIM All-Share.