JPY pairs Lot Size calculation

[Nuno Madeira Amaro Pire Costa]

Hi all.

This code works well on other pairs but in xxxJPY pairs I get 10x the desired lotsize. I used to code in MT4 and am now learning the ropes on MT5.

In MT4 I recall I used to check Digits. This is meant only for FX majors, so I assumed "point" = tick. Is it not so in some pairs?

This is my SetSize code:

double SetSize(int index) {return SetSize(index,SymbolList[index]);} // Se entrar com indice, reinicia com par
double SetSize(int i, string par) {
   double point=SymbolInfoDouble(par,SYMBOL_POINT);
   double lotSize=((Risk/stopLossDistance)/SymbolInfoDouble(par,SYMBOL_TRADE_TICK_VALUE));
printf("Size for "+par+"= "+lotSize);
printf("StopLossDistance "+par+"= "+stopLossDistance);
   lotSize=NormalizeDouble(lotSize,2);
   LotSizeList[i]=lotSize;
printf("Size for "+par+"= "+lotSize);
   return(lotSize);
}

I have previously generated set the variables:

- Margin in USD

- stoplossDistance in number of POINTS (lets say 57, not 0.00057), not pips

- par = currency pair

[Nuno Madeira Amaro Pire Costa]

Do I have to do shenanigans like converting points for points?

As in:

double SetSize(int index) {return SetSize(index,SymbolList[index]);} // Se entrar com indice, reinicia com par
double SetSize(int i, string par) {
   double point=SymbolInfoDouble(par,SYMBOL_POINT);
   double lotSize=((Risk/stopLossDistance)/SymbolInfoDouble(par,SYMBOL_TRADE_TICK_VALUE));


   DecimalJPYconverter=SymbolInfoDouble(par,SYMBOL_POINT)/SymbolInfoDouble(EURUSD,SYMBOL_POINT);
   lotSize = lotSize*DecimalJPYconverter;

printf("Size for "+par+"= "+lotSize);
printf("StopLossDistance "+par+"= "+stopLossDistance);
   lotSize=NormalizeDouble(lotSize,2);
   LotSizeList[i]=lotSize;
printf("Size for "+par+"= "+lotSize);
   return(lotSize);
}

Where the decimal converter is 100 for xxJPY pairs and 1 for normal pairs?!? pls tell me there is a more elegant way!

[William Roeder]

 double lotSize=((Risk/stopLossDistance)/SymbolInfoDouble(par,SYMBOL_TRADE_TICK_VALUE));

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. 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 You place the stop where it needs to be — where the reason for the trade is no longer valid.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 FreeMargin 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.

[David Diez]

Nuno Costa:

Hi all.

This code works well on other pairs but in xxxJPY pairs I get 10x the desired lotsize. I used to code in MT4 and am now learning the ropes on MT5.

In MT4 I recall I used to check Digits. This is meant only for FX majors, so I assumed "point" = tick. Is it not so in some pairs?

This is my SetSize code:

I have previously generated set the variables:

- Margin in USD

- stoplossDistance in number of POINTS (lets say 57, not 0.00057), not pips

- par = currency pair

The same thig is happening on my computer, the problem besides on TickSize.

My computer shows a print of 100.0 tickvalue for JPY pairs, then I wrote these lines:

input bool TestMode = true; // Fix JPY tick (test only)
if(TestMode==true&&SDigits==3){STick=STick/100;} // Fixes JPY pairs tickvalue.

Keep in mind that XAG pairs may not work through this input.