Financial market		Community ecology	Denoted by
company	↔	species	i
market value of a company	↔	species biomass	vi
total market value	↔	total biomass (all species)	V
total market return	↔	rate of variation of the total biomass	R
market share of a company	↔	frequency of such species	xi
evenness (inverse of concentration)	↔	evenness (species diversity)	E