CAPM

Course details

No matter how much we diversify our investments, it's impossible to get rid of all the risk. As investors, we deserve a rate of return that compensates us for taking on risk. The capital asset pricing model (CAPM) helps us to calculate investment risk and what return on investment we should expect. Here we take a closer look at how it works.

Birth of a Model

The capital asset pricing model was the work of financial economist (and later, Nobel laureate in economics) William Sharpe, set out in his 1970 book "Portfolio Theory and Capital Markets." His model starts with the idea that individual investment contains two types of risk:

• Systematic Risk - These are market risks that cannot be diversified away. Interest rates, recessions and wars are examples of systematic risks.
  
• Unsystematic Risk - Also known as "specific risk," this risk is specific to individual stocks and can be diversified away as the investor increases the number of stocks in his or her portfolio. In more technical terms, it represents the component of a stock's return that is not correlated with general market moves.