محاسبه حجم معامله بر اساس درصد ریسک

double LotForRisk(string symbol, double riskMoney, double slPoints)
{
   double tickValue = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_VALUE);
   double tickSize  = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_SIZE);
   double point     = SymbolInfoDouble(symbol, SYMBOL_POINT);
   if(tickValue <= 0.0 || tickSize <= 0.0 || slPoints <= 0.0)
      return 0.0;

   // Perte en devise du compte pour 1 lot si le SL est touché
   double lossPerLot = slPoints * point / tickSize * tickValue;
   if(lossPerLot <= 0.0)
      return 0.0;

   return NormalizeLot(symbol, riskMoney / lossPerLot);
}

// Exemple : risquer 1% de l'équité sur un SL de 250 points
double risk = AccountInfoDouble(ACCOUNT_EQUITY) * 0.01;
double lot  = LotForRisk(_Symbol, risk, 250.0);