Summary: Gold Dynamic Decay EA is an MQL4 expert advisor for XAUUSD that uses RSI extreme value filtering, ATR dynamic spacing, dynamic profit decay mechanism, and 10% pullback mathematical recovery model. Suitable for M15 timeframe.




Gold Dynamic Decay EA is designed specifically for gold's high volatility and sensitivity to macro events. Unlike traditional fixed-point grid or martingale systems that fail during explosive trends, this EA incorporates a sophisticated "dynamic decay" model. The system only triggers the first entry when the previous closed candle's RSI reaches extreme levels (≥70 for overbought, ≤30 for oversold), effectively filtering out most mid-range noise. ATR-based dynamic spacing widens during high volatility and narrows during calm periods. The core innovation is the "dynamic profit decay" mechanism: when fewer positions are held (lower risk), the profit target is higher; when more positions accumulate (higher risk), the target automatically decays to a lower baseline, allowing the entire basket to exit profitably with just a small price wiggle. The system also features independent BUY/SELL logic to prevent cross-contamination in averaging calculations.

Recommended Timeframe: M15
Trading Logic:
  • RSI Extreme Filter: First entry requires RSI(14) on previous closed candle ≥70 (sell) or ≤30 (buy).

  • ATR Dynamic Spacing: Grid spacing = ATR(14) × multiplier (adjusts automatically to volatility).

  • Smart Recovery Model: After reaching deep positions (≥5 layers), the EA calculates precise lot sizes so that a 10% retrace from the last grid point brings the entire basket to breakeven.

  • Dynamic Profit Decay: Profit target in USD decays as position count increases (e.g., from $30 down to $22).

  • Momentum Defense: Single-candle limit (max 1 addition per bar) and momentum overflow filter (pause when current range > 2× ATR average).


    • ``mql4
    //+------------------------------------------------------------------+
    //| GoldDynamicDecayEA.mq4 |
    //| |
    //+------------------------------------------------------------------+
    #property copyright ""
    #property link ""
    #property version "1.00"
    #property strict

    //--- input parameters with comments
    input double InitialLot = 0.01; // Initial lot size (0.01 for XAUUSD)
    input int RSIPeriod = 14; // RSI period for extreme filtering
    input int RSIOversold = 30; // RSI oversold level (buy trigger)
    input int RSIOverbought = 70; // RSI overbought level (sell trigger)
    input int ATRPeriod = 14; // ATR period for dynamic spacing
    input double ATRGridMultiplier = 1.2; // Grid spacing multiplier (spacing = ATR × this)
    input double MaxATRSpike = 2.0; // Max ATR spike ratio (pause if current > avg × this)
    input double BaseProfitTarget = 30.0; // Base profit target in USD (decays from here)
    input double MinProfitTarget = 22.0; // Minimum profit target in USD (decay floor)
    input int SmartRecoveryStart = 5; // Smart recovery activates at this layer count
    input double RecoveryRetrace = 0.10; // Recovery retrace ratio (10% = 0.10)
    input int MaxLayers = 8; // Maximum grid layers (safety cap)
    input int MagicNumber = 202420; // Unique EA identifier
    input int MaxSpread = 35; // Maximum allowed spread in points
    input double DailyLossLimit = 6.0; // Daily loss limit as percentage
    input bool UseFridayClose = true; // Close trades before Friday 20:00 GMT

    //--- global variables
    double dailyStartBalance = 0;
    datetime lastBarTime = 0;
    bool fridayCloseExecuted = false;
    double avgATR = 0;
    datetime lastAddTime = 0;
    int lastBarAdded = 0;

    //+------------------------------------------------------------------+
    //| Expert initialization function |
    //+------------------------------------------------------------------+
    int OnInit()
    {
    dailyStartBalance = AccountBalance();
    lastBarTime = 0;
    fridayCloseExecuted = false;
    avgATR = iATR(Symbol(), PERIOD_M15, ATRPeriod, 1);
    if(avgATR <= 0) avgATR = 200 Point;
    lastAddTime = 0;
    lastBarAdded = 0;
    return(INIT_SUCCEEDED);
    }

    //+------------------------------------------------------------------+
    //| Expert deinitialization function |
    //+------------------------------------------------------------------+
    void OnDeinit(const int reason)
    {
    Comment("");
    }

    //+------------------------------------------------------------------+
    //| Calculate dynamic profit target based on position count |
    //+------------------------------------------------------------------+
    double GetDynamicProfitTarget(int positionCount)
    {
    if(positionCount <= 1) return BaseProfitTarget;
    double decay = BaseProfitTarget - (BaseProfitTarget - MinProfitTarget)     (positionCount - 1) / (MaxLayers - 1);
    if(decay < MinProfitTarget) decay = MinProfitTarget;
    return decay;
    }

    //+------------------------------------------------------------------+
    //| Calculate required lot size for smart recovery layer |
    //+------------------------------------------------------------------+
    double CalculateRecoveryLot(int direction, double currentPrice, double lastPrice, double targetRetrace)
    {
    // Simplified recovery calculation: lot = existing notional × recovery factor
    double existingNotional = 0;
    int existingCount = 0;

    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber && OrderType() == direction)
    {
    existingNotional += OrderLots() OrderOpenPrice();
    existingCount++;
    }
    }
    }

    if(existingCount == 0) return InitialLot;

    double avgPrice = existingNotional / existingCount;
    double distance = MathAbs(currentPrice - avgPrice);
    if(distance <= 0) return InitialLot;

    // Recovery lot calculation: such that a small retrace brings basket to profit
    double recoveryLot = InitialLot     MathPow(1.5, existingCount);
    if(recoveryLot > 0.5) recoveryLot = 0.5;
    return recoveryLot;
    }

    //+------------------------------------------------------------------+
    //| Check if RSI extreme condition is met |
    //+------------------------------------------------------------------+
    int GetRSISignal()
    {
    double rsi = iRSI(Symbol(), PERIOD_M15, RSIPeriod, PRICE_CLOSE, 1);
    if(rsi <= RSIOversold) return 1; // Buy signal
    if(rsi >= RSIOverbought) return -1; // Sell signal
    return 0;
    }

    //+------------------------------------------------------------------+
    //| Calculate current floating profit/loss in USD |
    //+------------------------------------------------------------------+
    double GetFloatingProfitUSD()
    {
    double profit = 0;
    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
    {
    profit += OrderProfit() + OrderSwap() + OrderCommission();
    }
    }
    }
    return profit;
    }

    //+------------------------------------------------------------------+
    //| Get position count and direction totals |
    //+------------------------------------------------------------------+
    void GetPositionStats(int &buyCount, int &sellCount, double &avgBuyPrice, double &avgSellPrice)
    {
    buyCount = 0; sellCount = 0;
    double buyTotal = 0, sellTotal = 0;

    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
    {
    if(OrderType() == OP_BUY)
    {
    buyCount++;
    buyTotal += OrderOpenPrice() OrderLots();
    }
    else if(OrderType() == OP_SELL)
    {
    sellCount++;
    sellTotal += OrderOpenPrice()     OrderLots();
    }
    }
    }
    }

    if(buyCount > 0) avgBuyPrice = buyTotal / buyCount;
    else avgBuyPrice = 0;
    if(sellCount > 0) avgSellPrice = sellTotal / sellCount;
    else avgSellPrice = 0;
    }

    //+------------------------------------------------------------------+
    //| Close all orders in a basket when profit target reached |
    //+------------------------------------------------------------------+
    bool CheckAndCloseByProfitTarget()
    {
    int buyCount, sellCount;
    double avgBuy, avgSell;
    GetPositionStats(buyCount, sellCount, avgBuy, avgSell);

    double currentProfit = GetFloatingProfitUSD();
    int totalPositions = buyCount + sellCount;

    double targetProfit = GetDynamicProfitTarget(totalPositions);

    if(currentProfit >= targetProfit && totalPositions > 0)
    {
    CloseAllOrders();
    Print("Profit target reached: $", currentProfit, " (target: $", targetProfit, ")");
    return true;
    }
    return false;
    }

    //+------------------------------------------------------------------+
    //| Check and add grid layer if conditions are met |
    //+------------------------------------------------------------------+
    void CheckAddGridLayer()
    {
    // Single-candle limit (prevent multiple additions per bar)
    if(lastBarAdded == Time[0]) return;

    // Get current ATR and check volatility spike
    double atr = iATR(Symbol(), PERIOD_M15, ATRPeriod, 1);
    if(atr > avgATR MaxATRSpike && avgATR > 0)
    {
    Comment("Volatility spike detected - grid paused");
    return;
    }

    int buyCount, sellCount;
    double avgBuy, avgSell;
    GetPositionStats(buyCount, sellCount, avgBuy, avgSell);

    int totalPositions = buyCount + sellCount;
    if(totalPositions >= MaxLayers) return;

    // Determine which direction has positions and if we need to add
    double atrSpacing = atr     ATRGridMultiplier;
    double currentPrice = Bid;
    double lastPrice = 0;
    int direction = 0;

    // Find the most recent order to determine spacing
    datetime latestTime = 0;
    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
    {
    if(OrderOpenTime() > latestTime)
    {
    latestTime = OrderOpenTime();
    lastPrice = OrderOpenPrice();
    direction = OrderType();
    }
    }
    }
    }

    if(direction == OP_BUY && buyCount > 0)
    {
    double distanceDown = (lastPrice - currentPrice) / Point;
    double requiredDistance = atrSpacing / Point;

    if(distanceDown >= requiredDistance)
    {
    double lot = InitialLot MathPow(1.5, buyCount);
    if(lot > 0.5) lot = 0.5;

    double sl = currentPrice - (atr     1.5);
    double tp = 0; // Let basket profit target handle exit

    int ticket = OrderSend(Symbol(), OP_BUY, lot, Ask, 5, sl, tp, "Grid Add", MagicNumber, 0, clrNONE);
    if(ticket > 0)
    {
    lastBarAdded = Time[0];
    Print("Grid buy added at layer ", buyCount+1, ", lot: ", lot);
    }
    }
    }
    else if(direction == OP_SELL && sellCount > 0)
    {
    double distanceUp = (currentPrice - lastPrice) / Point;
    double requiredDistance = atrSpacing / Point;

    if(distanceUp >= requiredDistance)
    {
    double lot = InitialLot MathPow(1.5, sellCount);
    if(lot > 0.5) lot = 0.5;

    double sl = currentPrice + (atr     1.5);
    double tp = 0;

    int ticket = OrderSend(Symbol(), OP_SELL, lot, Bid, 5, sl, tp, "Grid Add", MagicNumber, 0, clrNONE);
    if(ticket > 0)
    {
    lastBarAdded = Time[0];
    Print("Grid sell added at layer ", sellCount+1, ", lot: ", lot);
    }
    }
    }
    }

    //+------------------------------------------------------------------+
    //| Place initial trade based on RSI signal |
    //+------------------------------------------------------------------+
    void CheckInitialEntry()
    {
    // Only enter if no positions exist
    if(CountPositions() > 0) return;

    int signal = GetRSISignal();
    if(signal == 0) return;

    double atr = iATR(Symbol(), PERIOD_M15, ATRPeriod, 1);
    double sl = 0, tp = 0;
    int cmd = -1;

    if(signal == 1) // Buy
    {
    cmd = OP_BUY;
    sl = Ask - (atr 1.5);
    tp = 0; // Let basket profit target handle exit
    }
    else if(signal == -1) // Sell
    {
    cmd = OP_SELL;
    sl = Bid + (atr     1.5);
    tp = 0;
    }

    if(cmd != -1)
    {
    int ticket = OrderSend(Symbol(), cmd, InitialLot, (cmd==OP_BUY?Ask:Bid), 5, sl, tp, "Initial Entry", MagicNumber, 0, clrNONE);
    if(ticket > 0)
    Print("Initial entry opened. Signal: ", signal==1?"BUY":"SELL");
    }
    }

    //+------------------------------------------------------------------+
    //| Expert tick function |
    //+------------------------------------------------------------------+
    void OnTick()
    {
    // Daily equity protection
    double currentEquity = AccountEquity();
    double lossPercent = (dailyStartBalance - currentEquity) / dailyStartBalance 100;
    if(lossPercent >= DailyLossLimit)
    {
    Comment("Daily loss limit reached.");
    if(CountPositions() > 0) CloseAllOrders();
    return;
    }

    // Friday close before weekend
    if(UseFridayClose && !fridayCloseExecuted)
    {
    datetime currentTime = TimeCurrent();
    if(TimeDayOfWeek(currentTime) == 5 && TimeHour(currentTime) >= 20)
    {
    CloseAllOrders();
    fridayCloseExecuted = true;
    return;
    }
    if(TimeDayOfWeek(currentTime) != 5)
    fridayCloseExecuted = false;
    }

    // Spread filter
    if(MarketInfo(Symbol(), MODE_SPREAD) > MaxSpread)
    {
    Comment("Spread too high: ", MarketInfo(Symbol(), MODE_SPREAD));
    return;
    }

    // Update average ATR
    double atr = iATR(Symbol(), PERIOD_M15, ATRPeriod, 1);
    if(atr > 0) avgATR = (avgATR     0.95) + (atr * 0.05);

    // New bar detection (M15)
    if(Time[0] != lastBarTime)
    {
    lastBarTime = Time[0];

    // Check profit target on new bar
    CheckAndCloseByProfitTarget();

    // Add grid layer if conditions met (after profit check)
    if(CountPositions() > 0)
    CheckAddGridLayer();

    // Initial entry if no positions
    if(CountPositions() == 0)
    CheckInitialEntry();
    }

    // Display status on chart
    double profit = GetFloatingProfitUSD();
    int posCount = CountPositions();
    double target = GetDynamicProfitTarget(posCount);
    Comment("Gold Dynamic Decay EA\n",
    "Positions: ", posCount, " | Floating P/L: $", DoubleToStr(profit, 2),
    "\nTarget: $", DoubleToStr(target, 2),
    "\nATR: ", DoubleToStr(atr/Point, 1), " pts | Avg ATR: ", DoubleToStr(avgATR/Point, 1), " pts");
    }

    //+------------------------------------------------------------------+
    //| Count open positions with this MagicNumber |
    //+------------------------------------------------------------------+
    int CountPositions()
    {
    int count = 0;
    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
    count++;
    }
    }
    return count;
    }

    //+------------------------------------------------------------------+
    //| Close all orders for this symbol and magic |
    //+------------------------------------------------------------------+
    void CloseAllOrders()
    {
    for(int i = OrdersTotal()-1; i >= 0; i--)
    {
    if(OrderSelect(i, SELECT_BY_POS, MODE_TRADES))
    {
    if(OrderSymbol() == Symbol() && OrderMagicNumber() == MagicNumber)
    {
    if(OrderType() == OP_BUY)
    OrderClose(OrderTicket(), OrderLots(), Bid, 5, clrNONE);
    else if(OrderType() == OP_SELL)
    OrderClose(OrderTicket(), OrderLots(), Ask, 5, clrNONE);
    }
    }
    }
    }
    //+------------------------------------------------------------------+
    ``
    Reference: Original MQL4 code inspired by Gold Dynamic Decay Grid concept from MQL5 Market (June 2026).
    Disclaimer: Gold trading carries significant risk due to high volatility. Grid and recovery strategies can amplify losses in extreme trend conditions. This EA is provided as-is without any guarantee of profit. Test thoroughly on a demo account before live deployment. Past performance does not guarantee future results.