Need some help, this Function is returning the wrong lotsizes

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//+------------------------------------------------------------------+
//| Calculate lot size based on risk percentage                      |
//+------------------------------------------------------------------+
double CalculateLotSize(string symbol, double accountBalance, double stopLossPoints, double riskPercentage)
{
    // Get symbol properties
    double tickSize = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_SIZE);
    double tickValue = SymbolInfoDouble(symbol, SYMBOL_TRADE_TICK_VALUE);
    double pointValue = SymbolInfoDouble(symbol, SYMBOL_POINT);

    // Calculate risk amount in account currency
    double riskAmount = accountBalance * (riskPercentage / 100.0);

    // Calculate lot size
    double lotSize = riskAmount / (stopLossPoints * tickValue / pointValue);

    Print("Symbol: ", symbol, ", Account Balance: ", accountBalance, ", Risk Percentage: ", riskPercentage, ", Stop Loss Points: ", stopLossPoints, ", Risk Amount: ", riskAmount);
    Print("Tick Size: ", tickSize, ", Tick Value: ", tickValue, ", Point Size: ", pointValue, ", Point Value: ", pointValue);
    Print("Calculated Lot Size: ", lotSize);

    return lotSize;
}


//Debug Prints

2024.07.19 14:20:23.925 gg EA v2.0 (USDCAD,M15) Setting stop loss for SELL: 1.37186
2024.07.19 14:20:23.925 gg EA v2.0 (USDCAD,M15) Symbol: USDCAD, Account Balance: 6856.4, Risk Percentage: 1.0, Stop Loss Points: 1.37186, Risk Amount: 68.564
2024.07.19 14:20:23.925 gg EA v2.0 (USDCAD,M15) Tick Size: 0.00001, Tick Value: 0.7291605903284141, Point Size: 0.00001, Point Value: 0.00001
2024.07.19 14:20:23.925 gg EA v2.0 (USDCAD,M15) Calculated Lot Size: 0.0006854300887845695
2024.07.19 14:20:23.925 gg EA v2.0 (USDCAD,M15) Adjusted lot size (below min limit): 0.01
  
 double lotSize = riskAmount / (stopLossPoints * tickValue / pointValue);

Risk depends on your initial stop loss, lot size, and the value of the symbol. It does not depend on margin or 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% account 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 You place the stop where it needs to be — where the reason for the trade is no longer valid.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. Then you compute your lot size.

  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.

 
William Roeder #:

Risk depends on your initial stop loss, lot size, and the value of the symbol. It does not depend on margin or leverage. 

A bold statement. The account leverage determines the lot size you are permitted to use. higher leverage will permit higher volume, and what do you think a larger lot size means? More risk. It's all correlated. A high leverage will enable a trader to take higher risk, which is what a lot of people want.

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