Range Expansion Index (MetaTrader indicator) is a relative oscillator indicator that measures the pace of the price changes and signals overbought/oversold states if the price demonstrates weakness or strength. It was developed by Tom DeMark and explained in his book The New Science of Technical Analysis. The value of the indicator changes from -100 to +100. REI is an enhanced oscillator because it tries to remain calm during the range trading and indicates signals only when the significant peaks or bottoms are spotted. You can download this indicator both for MT4 and MT5.
Tom DeMark suggested using the default period of 8. When the price goes above level 60 and the declines below it, the bearish signal is given. When the price goes below level -60 and then rises above it, the bullish signal is given. I find this indicator rather inaccurate (like all oscillators), but on the lower timeframes it can be quite useful.
Warning! Before you ask any basic questions regarding installation of the indicators, please, read this MetaTrader 4 Indicators Tutorial or MetaTrader 5 Indicators Tutorial to get the elementary knowledge on handling them.
Do you have any suggestions or questions regarding this indicator? You can always discuss Range Expansion Index with the other traders and MQL programmers on the indicators forums.