UK 100 is the FTSE 100 index in Britain and an important stock index in Europe. The index was compiled by FTSE Index Limited, a world-class index calculation financial institution. Starting from 1984, the most active 100 stocks in London Stock Exchange were specially selected. The constituent stocks cover 9 countries, mainly British companies, and other countries include Germany, France, Italy, Finland, Switzerland, Sweden, the Netherlands and Spain.

UK 100 is updated once every quarter, and it is called the three major European stock indexes together with CAC-40 index of France and Frankfurt index of Germany, and it is one of the important reference indicators for global investors.