Editing Sigma (section)

====Business, finance, and economics====
* In [[finance]], '''σ''' is the symbol used to represent [[Volatility (finance)|volatility]] of [[stock]]s, usually measured by the [[standard deviation]] of [[logarithmic return]]s.
* In [[accounting]], '''Σ''' indicates the [[Balance (accounting)|balance]] of invoice classes and the overall amount of debts and demands.
* In [[macroeconomics]], '''σ''' is used in equations to represent the [[elasticity of substitution]] between two inputs.
* In the [[machine industry]], [[Six Sigma]] ('''6σ''') is a quality model based on the [[standard deviation]].