The total risk of a share is the standard deviation of share price returns and is a measure of spread or volatility of those returns.

The systematic risk of a share is a measure of the sensitivity of the share price returns to the economy as a whole.

Default risk associated with a company failure can by significantly reduced by investing in a diversified portfolio of shares in many different companies.

Measures of risk with shares usually focus on the probability of making a loss when investing in the shares of a particular company.