In: Finance
If the covariance between the excess return of stock A and the market excess return is 0.03, the standard deviation of the market excess return is 0.15, and the standard deviation of the excess return of stock A is 0.25, what is the idiosyncratic volatility? What fraction of the total risk (variance) comes from the systematic risk (variance)?
Step 1 : Calculate the idiosyncratic volatility
The risk specifcally related to an asset or a particular investment is called idiosyncratic risk or firm related risk.
For ex : if there are floods in an area, only the firms having plants/offices in the inundated region will be affected by these floods.
Step 2: Fraction of the total risk coming from systematic risk
= Market Variance / Total Variance
= ~ 66.67%