Standard deviation is a metric that shows the variability of a security’s returns over time. It can be used to gauge volatility based on past performance and compare a future return to past returns.

For example, suppose that the manufacturing process described in the previous example produces engines whose weights are normally distributed with a mean of 1250 and a standard deviation of 12. The ...

Learn about downside deviation, a crucial metric for assessing downside risk by focusing on returns below a minimum threshold, and how it influences investment strategies.