Valor monetario de un punto para 1 lot

double PointValuePerLot(string symbol)
{
   double tickValue = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_VALUE);
   double tickSize  = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_SIZE);
   double point     = SymbolInfoDouble(symbol, SYMBOL_POINT);
   if(tickSize <= 0.0)
      return 0.0;
   return tickValue * (point / tickSize); // valeur d'UN point, pas d'un tick
}

// Exemple : montant risqué par une position existante
double slPoints = MathAbs(PositionGetDouble(POSITION_PRICE_OPEN)
                        - PositionGetDouble(POSITION_SL)) / _Point;
double risked = slPoints * PointValuePerLot(_Symbol)
              * PositionGetDouble(POSITION_VOLUME);
PrintFormat("Risque résiduel : %.2f %s", risked,
            AccountInfoString(ACCOUNT_CURRENCY));