MQL4 - Expert Advisor EMA issues at closing order

External question — Stack Overflow Stack Exchange Author: Haswellrefresh2 Original post: https://stackoverflow.com/questions/78397736 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I'm trying to build my own EA using EMA. When the program starts it will buy/sell according to the relative position of slow and fast EMA. Then the program should close the trade at the next EMA crossover. My first obstacle was to find a way to calculate EMA at the closing of candlestick, so I asked chatgpt to help me. After lots of attempts he brought me something using currenTime and prevTime values + the if condition. The calculations work even though i don't really understand why. I would be glad if someone can explain it to me. Now i'm struggling at closing my orders, when printing the EMA values I see the crossover but the program still won't close the trade. I'm sharing the code, i am backtesting it on GBP/JPY on M15 from 24 apr to 25 apr, there are 2 crossovers ( picture ), the program should run 3 trades on that day. Any help? here's my code below. //+------------------------------------------------------------------+ //| EACrossover.mq4 | //| Copyright 2024, Company Name | //| http://www.company.net | //+------------------------------------------------------------------+ #property strict // Global variables input int fastEMA_Length = 9; // Length of fast EMA input int slowEMA_Length = 21; // Length of slow EMA input double lotSize = 0.1; // Lot size input int slippage = 3; // slippage input int magicNumber = 123456; // magic number int buy_ticket, sell_ticket; // variables that store the OrderSend values bool buying_order=false; bool selling_order=false; int i = 0; // bar counter datetime prevTime = 0; // Variable to store the time of the previous tick (Created by ChatGPT) // It is used for the calculation of EMA at the closure of candlestick //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ int OnInit() { Print("EA Initialization"); return(INIT_SUCCEEDED); } //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ void OnTick() { datetime currentTime = Time[0]; // Get the time of the current tick // Check if the current tick is on a new bar by comparing its time with the previous tick if(currentTime != prevTime) { // Update the previous tick time with the current tick time prevTime = currentTime; i++; // Increment the bar counter // Calculate the EMAs for the current bar double currentFastEMA = iMA(NULL, 0, fastEMA_Length, 0, MODE_EMA, PRICE_CLOSE, 0); double currentSlowEMA = iMA(NULL, 0, slowEMA_Length, 0, MODE_EMA, PRICE_CLOSE, 0); if(OrdersTotal() == 0) // We open a trade when there is no trade actually opened { // Check EMA position to buy or sell if(currentFastEMA > currentSlowEMA) { buy_ticket = OrderSend(Symbol(), OP_BUY, lotSize, Ask, slippage, 0, 0, "", magicNumber, 0, Green); buying_order=true; Print("I'm buying !"); } else { sell_ticket = OrderSend(Symbol(), OP_SELL, lotSize, Bid, slippage, 0, 0, "", magicNumber, 0, Green); selling_order=true; Print("I'm selling !"); } } else { Print("FastEMA=",currentFastEMA," slowEMA=",currentSlowEMA," iteration n°",i); // If a trade is opened we decide to close it at the next EMA crossover if(buying_order==true) //closing buying order { if(currentFastEMA < currentSlowEMA) { OrderClose(buy_ticket,lotSize, PRICE_CLOSE,slippage,clrNONE); } buying_order=false; } if(selling_order==true) //closing selling order { if(currentFastEMA > currentSlowEMA) { OrderClose(sell_ticket,lotSize,PRICE_CLOSE,slippage,clrNONE); } selling_order=false; } } } } Sometime I have the error 138 depending TF.

External answer — Stack Overflow Stack Exchange Author: Haswellrefresh2 Original post: https://stackoverflow.com/a/78410368 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. To close a buy order one must close it at bid price. To close a sell order one must close it at ask price. That means we rewrite the code : if(buying_order && currentFastEMA < currentSlowEMA) //closing buy order { OrderClose(buy_ticket,lotSize, **Bid**,slippage,clrNONE); buying_order=false; } if(selling_order && currentFastEMA > currentSlowEMA) //closing sell order { OrderClose(sell_ticket,lotSize,**Ask**,slippage,clrNONE); selling_order=false; }