MQL4 ignoring a significant calculation when calculating tp/sl

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Morning all, 

I currently have a formula which calculates the SL and the TP. It calculates the TP/SL as a percentage of the current account balance The formula is as follows:


int OnInit(){

      
int    percent       = 2; //The amount to risk as a percentage of the account balance.
      double convert       = percent / 100; //Convert this into a decimal
      double stopLossl     = NormalizeDouble(Point*(AccountBalance() * convert),Digits); //Convert decimal into pips to risk (= 0.200).
      double yourStopLoss  = (63.600 - stopLossl); illustrated Ask price minus the number of pips to risk

      Print("The SL is "+DoubleToString(yourStopLoss ,Digits)); 

}

However, It's completely ignoring the 'convert' calculation and returning the illustrated Ask price figure  instead.

2023.01.18 13:24:36.544 hammertime_8.0.3 NZDJPY,H1: The SL is 63.600

I have isolated the issue to the percentage conversion because running the following code:

int OnInit(){


      double stopLossl     = NormalizeDouble(Point*(AccountBalance() * 0.02),Digits); //Convert decimal into pips to risk.
      double yourStopLoss  = (63.600 - stopLossl); illustrated Ask price minus the number of pips to risk

      Print("The SL is "+DoubleToString(yourStopLoss ,Digits)); 

}


Will give me the result of:

2023.01.18 13:29:54.734 hammertime_8.0.3 NZDJPY,H1: The SL is 63.400

which would be correct (£10,000 * (2 / 100) = 200).

I don't see why MQL4 is ignoring the percentage to decimal conversion when all the variables have been declared. 

 
TheHonestPrussian: Morning all, I currently have a formula which calculates the SL and the TP. It calculates the TP/SL as a percentage of the current account balance The formula is as follows: However, It's completely ignoring the 'convert' calculation and returning the illustrated Ask price figure  instead. 2023.01.18 13:24:36.544 hammertime_8.0.3 NZDJPY,H1: The SL is 63.600 I have isolated the issue to the percentage conversion because running the following code: Will give me the result of: 2023.01.18 13:29:54.734 hammertime_8.0.3 NZDJPY,H1: The SL is 63.400 which would be correct (£10,000 * (2 / 100) = 200). I don't see why MQL4 is ignoring the percentage to decimal conversion when all the variables have been declared. 

You are doing integer arithmetic. Choose one of the following options ...

Either this ...

double percent = 2.0; //The amount to risk as a percentage of the account balance.

or this ...

double convert  = percent / 100.0; //Convert this into a decimal

or this ...

double convert  = (double) percent / 100; //Convert this into a decimal

This is because ...

2   / 100   = 0        integer arithmetic
2   / 100.0 = 0.02     floating point arithmetic
2.0 / 100   = 0.02     floating point arithmetic
 
Fernando Carreiro #:

You are doing integer arithmetic. Choose one of the following options ...

Either this ...

or this ...

or this ...

Legend! Sorted.

IFor anyone else have the same issue, the code was changed to the following:

int OnInit(){

      
double percent       = 2.0; //The amount to risk as a percentage of the account balance.
double convert       = percent / 100; //Convert this into a decimal
double stopLossl     = NormalizeDouble(Point*(AccountBalance() * convert),Digits); //Convert decimal into pips to risk (= 0.200).
double yourStopLoss  = (63.600 - stopLossl); illustrated Ask price minus the number of pips to risk

	Print("The SL is "+DoubleToString(yourStopLoss ,Digits)); 

}
 
TheHonestPrussian:
      double stopLossl     = NormalizeDouble(Point*(AccountBalance() * 0.02),Digits); //Convert decimal into pips to risk.

Risk depends on your initial stop loss, lot size, and the value of the symbol. It does not depend on margin and leverage. No SL means you have infinite risk (on leveraged symbols). Never risk more than a small percentage of your trading funds, certainly less than 2% per trade, 6% total.

  1. You place the stop where it needs to be — where the reason for the trade is no longer valid. E.g. trading a support bounce, the stop goes below the support.

  2. AccountBalance * percent/100 = RISK = OrderLots * (|OrderOpenPrice - OrderStopLoss| * DeltaPerLot + CommissionPerLot) (Note OOP-OSL includes the spread, and DeltaPerLot is usually around $10/PIP, but it takes account of the exchange rates of the pair vs. your account currency.)

  3. Do NOT use TickValue by itself - DeltaPerLot and verify that MODE_TICKVALUE is returning a value in your deposit currency, as promised by the documentation, or whether it is returning a value in the instrument's base currency.
              MODE_TICKVALUE is not reliable on non-fx instruments with many brokers - MQL4 programming forum (2017)
              Is there an universal solution for Tick value? - Currency Pairs - General - MQL5 programming forum (2018)
              Lot value calculation off by a factor of 100 - MQL5 programming forum (2019)

  4. You must normalize lots properly and check against min and max.

  5. You must also check Free Margin to avoid stop out

  6. For MT5, see 'Money Fixed Risk' - MQL5 Code Base (2017)

Most pairs are worth about $10 per PIP. A $5 risk with a (very small) 5 PIP SL is $5/$10/5 or 0.1 Lots maximum.

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