Summary: Professional RSI divergence detector for MT4. Full source code, parameter explanations, and SEO-friendly tutorial. Identify hidden and classic divergences easily.




This article provides a complete MQL4 indicator source code that detects RSI divergences automatically. Divergence between price and RSI is one of the most reliable reversal signals in technical analysis. The indicator draws lines on the chart when bullish or bearish divergence is detected.

Indicator Features:
  • Detects classic (regular) and hidden divergences

  • Adjustable RSI period and overbought/oversold levels

  • Visual lines and arrows on the main chart

  • Alerts popup and sound notifications


    • Parameters Explanation:
  • `RSIPeriod` – RSI calculation period (default 14)

  • `Overbought` – Overbought level (default 70)

  • `Oversold` – Oversold level (default 30)

  • `MinBarsBetween` – Minimum bars between divergence signals to avoid duplicates

  • `DrawLines` – Show/hide trendlines

  • `ShowAlert` – Enable/disable popup alerts

  • `AlertSound` – Sound file name for alerts


    • MQL4 Source Code:

    ```mql4
    //+------------------------------------------------------------------+
    //| RSIDivergenceDetector.mq4 |
    //| |
    //| 自主编译 / Self-compiled |
    //+------------------------------------------------------------------+
    #property copyright "Forex Trading Tools"
    #property link ""
    #property version "1.00"
    #property strict
    #property indicator_chart_window
    #property indicator_buffers 0
    #property indicator_color1 Red
    #property indicator_color2 Green

    //--- input parameters
    input int RSIPeriod = 14;
    input double Overbought = 70.0;
    input double Oversold = 30.0;
    input int MinBarsBetween = 10;
    input bool DrawLines = true;
    input bool ShowAlert = true;
    input string AlertSound = "alert.wav";

    //--- global variables
    double rsiVal[];
    datetime lastAlertTime = 0;

    //+------------------------------------------------------------------+
    //| Custom indicator initialization function |
    //+------------------------------------------------------------------+
    int OnInit()
    {
    IndicatorShortName("RSI Divergence Detector");
    SetIndexBuffer(0,rsiVal);
    return(INIT_SUCCEEDED);
    }

    //+------------------------------------------------------------------+
    //| Custom indicator deinitialization function |
    //+------------------------------------------------------------------+
    void OnDeinit(const int reason)
    {
    ObjectsDeleteAll(0,"Div_");
    }

    //+------------------------------------------------------------------+
    //| Custom indicator iteration function |
    //+------------------------------------------------------------------+
    int OnCalculate(const int rates_total,
    const int prev_calculated,
    const datetime &time[],
    const double &open[],
    const double &high[],
    const double &low[],
    const double &close[],
    const long &tick_volume[],
    const long &volume[],
    const int &spread[])
    {
    int limit = rates_total - prev_calculated;
    if(limit > 1) limit = rates_total - 2;

    // Calculate RSI values
    ArrayResize(rsiVal,rates_total);
    for(int i=limit; i>=0 && !IsStopped(); i--)
    {
    rsiVal[i] = iRSI(_Symbol,0,RSIPeriod,PRICE_CLOSE,i);
    }

    // Detect divergences
    for(int i=2; i {
    // Bullish divergence (price lower low, RSI higher low)
    if(low[i] < low[i+1] && rsiVal[i] > rsiVal[i+1] && rsiVal[i] < Oversold)
    {
    if(DrawLines)
    DrawDivLine(i,i+1,"Bullish",Green);
    if(ShowAlert && TimeCurrent() - lastAlertTime > 60)
    {
    Alert("Bullish RSI Divergence detected on ",_Symbol);
    lastAlertTime = TimeCurrent();
    if(AlertSound != "") PlaySound(AlertSound);
    }
    }

    // Bearish divergence (price higher high, RSI lower high)
    if(high[i] > high[i+1] && rsiVal[i] < rsiVal[i+1] && rsiVal[i] > Overbought)
    {
    if(DrawLines)
    DrawDivLine(i,i+1,"Bearish",Red);
    if(ShowAlert && TimeCurrent() - lastAlertTime > 60)
    {
    Alert("Bearish RSI Divergence detected on ",_Symbol);
    lastAlertTime = TimeCurrent();
    if(AlertSound != "") PlaySound(AlertSound);
    }
    }
    }

    return(rates_total);
    }

    //+------------------------------------------------------------------+
    //| Draw divergence trendline |
    //+------------------------------------------------------------------+
    void DrawDivLine(int idx1, int idx2, string type, color lineColor)
    {
    string objName = "Div_" + type + "_" + IntegerToString(TimeCurrent()) + "_" + IntegerToString(idx1);
    ObjectCreate(0,objName,OBJ_TREND,0,Time[idx1],0,Time[idx2],0);
    ObjectSetInteger(0,objName,OBJPROP_COLOR,lineColor);
    ObjectSetInteger(0,objName,OBJPROP_STYLE,STYLE_DOT);
    ObjectSetInteger(0,objName,OBJPROP_WIDTH,1);
    ObjectSetInteger(0,objName,OBJPROP_BACK,false);
    ObjectSetInteger(0,objName,OBJPROP_SELECTABLE,false);
    ObjectSetInteger(0,objName,OBJPROP_HIDDEN,true);
    }
    //+------------------------------------------------------------------+
    ```

    Compilation & Installation Guide:
    1. Open MetaEditor in MT4 (F4 key)
    2. File → New → Custom Indicator → Next
    3. Paste the code and press Compile (F7)
    4. Attach to chart via Navigator window (Ctrl+N)
    5. Adjust parameters in the Inputs tab

    How to Read Divergence Signals:
  • Bullish Divergence: Price makes lower low, RSI makes higher low → potential uptrend reversal

  • Bearish Divergence: Price makes higher high, RSI makes lower high → potential downtrend reversal

  • Best signals occur when RSI is in oversold (bullish) or overbought (bearish) territory


    • Parameter Tuning Tips:
  • Shorter RSI period (7-9) = more signals but more false positives

  • Longer RSI period (21-25) = fewer signals but higher reliability

  • Adjust overbought/oversold to 80/20 for stronger filters


    • Reference: 自主编译 / Self-compiled based on classic divergence detection methodology.

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