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.

How They Differ and Practical Uses in Finance and Investing Henry Hoenig has three decades of journalism experience as a news and economics editor in the U.S. and Asia, handling coverage of global ...

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Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Andy Smith is a Certified Financial Planner ...

In response to my article, Is the Stock Market Too Concentrated?, which relied upon standard-deviation calculations to assess investment risk, a reader wrote: “My problem [with your argument] is ...