The FTSE 250 index is one of many indexes associated with the London Stock Exchange. An index is nothing more than a collection of companies. An index's composition is determined by the entire market value of a company's shares.

FTSE indices are well-known stock market indices in the United Kingdom. FTSE stands for the Financial Times Stock Exchange. The London Stock Exchange and the Financial Times previously owned a part of the index. The FTSE indices are now managed by FTSE Russell, a subsidiary of the London Stock Exchange Group.

The FTSE 250 Index is a measurement of the performance of the top 250 companies ranked by revenue. The index includes companies based in the United Kingdom, Europe, and internationally.