When you have the average production of three machines, it is easy to calculate the average or mean production. You just add ...

Standard deviation measures how far numbers in a data set are spread out from an average value. In investing, it is used as a measurement of portfolio volatility.

How to Interpret Standard Deviation. In the example above for Apple, the data show that the average return for the three-month period was 0.08 percent.

Standard deviation — also referred to by the Greek letter sigma (σ) — measures how far an asset's returns have been from its average return, ...

Standard deviation is calculated by first subtracting the mean from each value, and then squaring, adding, and averaging the differences to produce the variance.

Were that to occur, the standard-deviation calculation would be unfair, because it would penalize fund managers for excelling at their jobs. If a fund gains 7% when the stock market rises by 5% ...

The Standard Deviation is a term used in statistics. The term describes how much the numbers if a set of data vary from the mean. The syntax to calculate the Standard Deviation is as follows: ...

Standard deviation only measures stability, relative to the recent past, not expected future performance. To understand the shortcomings of this approach, look at the Bloomberg Aggregate Bond Index.

Doing this gives a monthly standard deviation (volatility) of 17.9% for Stock A and just 3.6% for Stock B. This confirms the optics in the chart. In other words, Stock A is a more volatile ...