Automated Trailing Stop Loss EA for MT5: ATR Buffer Formula & Source Code

Why Fixed Pip Trailing Stops Fail in Volatile Markets

Traditional fixed trailing stops (e.g., trailing by 20 pips) fail because they treat high-volatility sessions identically to quiet consolidations. During the New York Open, standard 1-minute gold volatility easily reaches 35 pips, instantly stopping out profitable positions before major trend expansions. The professional solution is an ATR-Normalized Volatility Trailing Stop:

# Dynamic Trailing Stop Distance Formula
Trailing_Distance = ATR(Period=14, Timeframe=H1) * ATR_Multiplier (e.g., 1.5)

Production MQL5 Expert Advisor Code (TrailingStop_ATR.mq5)

//+------------------------------------------------------------------+
//|                                           TrailingStop_ATR.mq5   |
//|                                  Copyright 2026, ForexAbad LLC   |
//|                             https://forexabad.com                |
//+------------------------------------------------------------------+
#property copyright "ForexAbad International Financial Research LLC"
#property link      "https://forexabad.com"
#property version   "1.00"
#property strict

#include <Trade\Trade.mqh>
CTrade trade;

input double InpAtrMultiplier = 1.5;   // ATR Volatility Multiplier
input int    InpAtrPeriod     = 14;    // ATR Period
input int    InpMinProfitPips = 10;    // Minimum profit before trail activates
input ulong  InpMagicNumber   = 78601; // Magic Number filter

int atrHandle;

int OnInit()
{
   trade.SetExpertMagicNumber(InpMagicNumber);
   atrHandle = iATR(_Symbol, PERIOD_CURRENT, InpAtrPeriod);
   if(atrHandle == INVALID_HANDLE)
   {
      Print("Failed to initialize ATR indicator handle");
      return INIT_FAILED;
   }
   return INIT_SUCCEEDED;
}

void OnDeinit(const int reason)
{
   IndicatorRelease(atrHandle);
}

void OnTick()
{
   double atrValues[1];
   if(CopyBuffer(atrHandle, 0, 0, 1, atrValues) <= 0) return;
   
   double currentAtr = atrValues[0];
   double trailDistance = currentAtr * InpAtrMultiplier;
   double point = _Point;
   
   for(int i = PositionsTotal() - 1; i >= 0; i--)
   {
      ulong ticket = PositionGetTicket(i);
      if(ticket <= 0) continue;
      if(PositionGetString(POSITION_SYMBOL) != _Symbol) continue;
      
      long type = PositionGetInteger(POSITION_TYPE);
      double openPrice = PositionGetDouble(POSITION_PRICE_OPEN);
      double currentSl = PositionGetDouble(POSITION_SL);
      double currentPrice = PositionGetDouble(POSITION_PRICE_CURRENT);
      
      if(type == POSITION_TYPE_BUY)
      {
         // Verify position is in profit past activation threshold
         if(currentPrice - openPrice >= InpMinProfitPips * point * 10)
         {
            double newSl = NormalizeDouble(currentPrice - trailDistance, _Digits);
            if(newSl > currentSl && newSl > openPrice)
            {
               trade.PositionModify(ticket, newSl, PositionGetDouble(POSITION_TP));
               PrintFormat("Position #%d Trailed SL updated to %f", ticket, newSl);
            }
         }
      }
      else if(type == POSITION_TYPE_SELL)
      {
         if(openPrice - currentPrice >= InpMinProfitPips * point * 10)
         {
            double newSl = NormalizeDouble(currentPrice + trailDistance, _Digits);
            if((newSl < currentSl || currentSl == 0) && newSl < openPrice)
            {
               trade.PositionModify(ticket, newSl, PositionGetDouble(POSITION_TP));
               PrintFormat("Position #%d Trailed SL updated to %f", ticket, newSl);
            }
         }
      }
   }
}

Verification & Backtesting Guidelines

When testing in the MetaTrader 5 Strategy Tester, select "Every tick based on real ticks" mode. Fixed-tick emulation introduces rounding artifacts that produce false trail triggers during spread spikes.