How to write an EA?

William Roeder  
larswidl: open buy position when … No TP or Stop loss.
  1. You have only four choices:

    1. Search for it (CodeBase or Market). Do you expect us to do your research for you?

    2. Try asking at:

    3. MT4: Learn to code it.
      MT5: Begin learning to code it.

      If you don't learn MQL4/5, there is no common language for us to communicate. If we tell you what you need, you can't code it. If we give you the code, you don't know how to integrate it into your code.

    4. Or pay (Freelance) someone to code it. Top of every page is the link Freelance.
                Hiring to write script - General - MQL5 programming forum (2019)

    We're not going to code it for you (although it could happen if you are lucky or the problem is interesting.) We are willing to help you when you post your attempt (using CODE button) and state the nature of your problem.
              No free help (2017)

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 You place the stop where it needs to be — where the reason for the trade is no longer valid.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

If you want to learn how to do it yourself, I suggest first starting by studying the examples provided in the MT5 platform. There is the "Moving Average" EA that you might want to look at. It's got a lot of things in it that you don't need and it might be difficult to understand if you don't have any coding experience with other languages, but it's still a good starting point.