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 ...

The following data set (WIRE) contains breaking strength measurements recorded in pounds per inch for 25 samples from a metal wire manufacturing process. The subgroup sample sizes vary between 3 and 7 ...

James Chen, CMT is an expert trader, investment adviser, and global market strategist. Khadija Khartit is a strategy, investment, and funding expert, and an educator of fintech and strategic finance ...

An animated guide explaining how the standard devition can give you a clearer picture of a sample than averages alone. An example involving zoo keepers and some very dangerous animals demonstrates ...

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 ...