KDJ indicator is a useful and popular free Forex indicator for MT4. It is used by many traders to identify potential trading opportunities and to help them make informed decisions. The KDJ indicator is based on the Stochastic Oscillator, which is a momentum indicator that measures the strength of a trend. The KDJ indicator combines the Stochastic Oscillator with two additional components: the RSI (Relative Strength Index) and the ADX (Average Directional Movement Index). The KDJ indicator is designed to identify overbought and oversold conditions in the market. When the KDJ indicator is above 80, it indicates that the market is overbought. Conversely, when the KDJ indicator is below 20, it indicates that the market is oversold. Traders can use this information to identify potential trading opportunities. For example, when the KDJ indicator is above 80, traders may look for short-selling opportunities, while when the KDJ indicator is below 20, traders may look for buying opportunities. Overall, the KDJ indicator is a useful and popular free Forex indicator for MT4. It can be used to identify overbought and oversold conditions, as well as potential reversal points.