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. 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.). The FT 30 index was calculated using the
geometric mean. 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==