# Std Deviation

## Standard Deviation

The Standard Deviation chart study plots the size of the standard deviation of the data over the given period (the period can be changed under "edit").

Standard deviation is a measure of how spread out the values in a data set are. More precisely, it is a measure of the average distance of the data values from their mean, or Simple Moving Average (SMA).

If the data points are all close to the mean, then the standard deviation will be low (closer to zero). If many data points are very different from the mean, then the standard deviation is high (further from zero). If all the data values are equal, then the standard deviation will be zero.

Parameters: Period.

For additional help on what the different parameters mean, that isn't included on this page, click here.

Standard Deviation

Here is an example of the Standard Deviation chart study (on a London Stock Exchange graph)

## In addition:

There is no maximum value, although it will be limited by the data set.

If you plot the SMA chart study, along with the standard deviation, you will see that the standard deviation of the data is highest when the gap between the SMA and the price level, at any one time, is greatest (see below).

Standard Deviation & Simple Moving Average

Here is an example of the Standard Seviation with the Simple Moving Average, and the price line (of the London Stock Exchange), and what it may indicate