Sometimes the market data follows normal distribution, in these cases it is more appropriate to utilize mean-based statistical techniques. This script plots the special case of seven-number summary with 1st, 2nd & 3rd standard deviations below and above the mean.
It also has "Log-space" switch which should be checked while using logarithmic scale.
The next...
Statistical methods based on mean cannot be effective all the time when attributed to financial data since it doesn't usually follow normal distribution, the data can be skewed or/and have extreme values which can be described as outliers.
In order to deal with this problem it is appropriate to use median-based techniques.
The most common one is called...
