Extreme value theory (EVT) aims to remedy a deficiency with value at risk (i.e., it gives no information about losses that exceed the VaR) and glaring weakness of delta normal value at risk (VaR): the dreaded-fat tails. The key is the idea that the tail has it's own "child" distribution.

This video explains the extreme value theory.

This video is developed by David from Bionic Turtle.