Chaikin's volatility indicator.
Quote from Technical Analysis from A to Z by S. Achelis:
There are two ways to interpret this measure of volatility. One method assumes that market tops are generally accompanied by increased volatility (as investors get nervous and indecisive) and that the latter stages of a market bottom are generally accompanied by decreased volatility (as investors get bored).
Another method (Mr. Chaikin's) assumes that an increase in the Volatility indicator over a relatively short time period indicates that a bottom is near (e.g., a panic sell-off) and that a decrease in volatility over a longer time period indicates an approaching top (e.g., a mature bull market). As with almost all experienced investors, Mr. Chaikin recommends that you do not rely on any one indicator. He suggests using a moving average penetration or trading band system to confirm this (or any) indicator.
The indicator uses SmoothAlgorithms.mqh library classes (must be copied to the terminal_data_folder\MQL5\Include). The use of the classes was thoroughly described in the article "Averaging Price Series for Intermediate Calculations Without Using Additional Buffers".
This indicator was first implemented in MQL4 and published in CodeBase on 08.02.2007.
Fig.1. Chaikin_Volatility Indicator
Translated from Russian by MetaQuotes Software Corp.
Original code: https://www.mql5.com/ru/code/2432
The Chaikin_Volatility indicator with the timeframe selection option available in input parameters.MFI_2HTF
A colored cloud formed by two MFI oscillators with different timeframes.