FTSE 100 Share Price Index

You've probably heard it called the FTSE 100, the FTSE or more informally the Footsie, but do you know what it is and how it came about?

Put into its simplest term, the FTSE 100 is a share index of the 100 most highly capitalised UK companies listed on the London Stock exchange.

The name itself, FTSE, is a combination of the two founding organisations which still maintain the index today as an independent company - the Financial Times and the London Stock Exchange.

The 100 blue chips selected are reviewed quarterly and make up over three-quarters of the total market capitalisation on the London Stock Exchange.

Glance down the list of 100 companies making up the index and you'll see familiar names like RBS, Barclays and Lloyds Banking as well as high-street brands such as Marks & Spencer, Thomas Cook and J Sainsbury.

And because the FTSE 100 is made up of the biggest market performers, it's the most widely used and referred to index in the news when discussing the success, or non-success, of particular businesses and the economy.

Trading on these companies takes place between 08:00 and 16.29 on the London Stock Exchange and is calculated and updated in real-time.

All stocks on the FTSE index group are free-float weighted so that companies are weighted by the total value of shares that are actually available to portfolio investors rather than the total market cap.

The FTSE 100 index was created in 1984 and has a net capitalisation of £1,622.47 billion (as of close of day 16/04/10 calculated by shareprices.com).