The FTSE is the Financial Times Stock Exchange index, a leading set of United Kingdom stock market indices. The Financial Times (or FT) is the UK's leading financial newspaper.

In common usage the FTSE (pronouncied futsee) refers to the FTSE 30 stock index which is an index of the 30 leading shares traded on the London Stock Exchange. However there are many other indices also within the FTSE stable including the FT-All Share index (covering the whole of the UK market) and FT indices that cover international stock markets and indeed the FT-World index.

These various FT indices are formally referred to as the FT Actuaries indices and the basis of construction is considered to be state-of-the-art; there are some indices around the world that use potentially misleading forms of calculation e.g. price rather than market capitalisation weighted price indices.

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