In this section, we refine our understanding of risk. Surprisingly, the concept of risk changes when the focus shifts from the risk of a single asset held in isolation to the risk of a portfolio of assets. Here, we examine different statistical methods to quantify risk; later, we apply those methods to portfolios.
The notion that risk is somehow connected to uncertainty is intuitive. The more uncertain you are about how an investment will perform, the riskier that investment seems. Scenario analysis provides a simple way to quantify that intuition, and probability distributions offer a more sophisticated method for analyzing the risk of an investment.
Scenario analysis uses ...