The Financial Times Stock Exchange 100 Index, also called the FTSE 100 Index, FTSE 100, FTSE, or, informally, the "Footsie", is the United Kingdom's best-known stock market index of the 100 most highly capitalised blue chip companies listed on the London Stock Exchange. Founded in 1984 by Stock Exchange to better reflect activity on the market, it replaced the Financial Times' own FT 30. A new index afforded Stock Exchange the opportunity to launch the options contract derived from the FTSE's real-time data, while competitors LIFFE launched the futures 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. Wikipedia