The FT 30 (FT Ordinary Index or FTOI, not "FTSE 30") is a stock market index managed by the Financial Times. As an index of stocks to represent the real trends on the market, the FT 30 has been superseded by the FTSE 100, which was introduced in 1984. It was relaunched with new components in 2025.
Background The purpose of the FT 30 was to give a selection of stocks, which capture the range and essence of UK companies. The index was devised in 1935 by Maurice Green and Otto Clarke of the Financial News and was termed the "Financial News 30-share index" until that paper merged with the Financial Times in 1945."Green, (James) Maurice Spurgeon", Oxford Dictionary of National Biography The companies listed in the index are made up of those in the industrial and commercial sectors. It excludes government stocks, and used to exclude financial sector (banks, insurance, etc.).See The Post-War History of the London Stock Market,
The FT 30 index was calculated using the geometric mean.The Financial System Today, by Eric E. Rowley. (Manchester University Press, 1987) As Rowley states, this understated movements in the index compared to using the arithmetic mean; and there are circumstances where this is undesirable.
See also UK company law FTSE 100 FTSE 250
References
Further reading Oxford Dictionary of Finance and Banking, Berger, D. & Jackson, B.; The Motley Fool UK Investment Workbook,
External links FT.com - FT 30 info