Platforms7 min read
How to Use Expert Advisors (EAs) in MetaTrader
An expert advisor, or EA, is a program written in MQL4 or MQL5 that runs inside MetaTrader and can open, manage and close trades automatically according to rules its author coded into it. EAs range from simple tools that just place a trailing stop, to full systems that scan multiple instruments and trade without any manual input at all.
MixFunded permits the use of expert advisors on both evaluation and funded accounts. That permission comes with a practical responsibility: an EA that trades while you are away from the screen can also breach a drawdown limit while you are away from the screen, so understanding how to set one up correctly matters as much as understanding what it does.
Installing and attaching an EA
EA files come as .ex4 (MT4) or .ex5 (MT5) compiled files, or as .mq4/.mq5 source files that need compiling first. In the terminal, open File, then Open Data Folder, then navigate to MQL4 or MQL5, then Experts, and copy the file into that folder. Restart MetaTrader or right-click Expert Advisors in the Navigator panel and select Refresh.
To run the EA, drag it from the Navigator onto the chart of the instrument you want it to trade. A settings window opens with two relevant tabs: Inputs, where the EA's own parameters live (lot size, stop distance, indicator settings), and Common, where you confirm Allow Algo Trading (MT5) or Allow live trading (MT4) is ticked. Without that tick, the EA loads but never places a trade.
AutoTrading and the toolbar switch
Beyond the per-EA setting, MetaTrader has a global AutoTrading button on the main toolbar. When it is off, no EA on any chart will trade even if individually enabled — it is a master switch, and it is worth checking first whenever an EA appears to be doing nothing.
A smiling face icon in the top-right corner of a chart indicates the EA is attached and active; a sad or neutral face indicates it is attached but not trading, usually because AutoTrading is off or a permission was not granted. Checking this icon is the fastest way to confirm an EA's actual status before assuming it has failed.
Magic numbers and running multiple EAs
A magic number is an identifying tag an EA assigns to the orders it places. It allows an EA to distinguish its own trades from manually placed ones or from another EA's trades on the same account, which matters when several strategies run at once on the same instrument — without unique magic numbers, one EA can inadvertently manage or close another's positions.
If you run more than one EA, check each one's default magic number in its Inputs tab and change them if they clash. This is a common source of unexplained behaviour when traders combine EAs downloaded from different sources.
The risks of unattended automation
An EA does not know it is trading on a drawdown-limited account unless it has been specifically coded to respect one. A strategy that performed well in isolation can still open a position sized for a normal account and breach a 5% daily loss limit in a single unfavourable move, with nobody watching to intervene.
Before running any EA live, test it on a demo account for long enough to see how it behaves in a losing sequence, not just a winning one. Confirm what happens around news releases, whether it uses a fixed lot size or a percentage-based one, and whether it has any internal daily-loss cutoff of its own. An EA left running unattended over a weekend or a holiday period is a common cause of accounts breaching limits that a trader would have caught manually.
- Check AutoTrading is enabled both globally and on the individual chart
- Give each EA a unique magic number if running more than one
- Confirm lot sizing is either fixed or correctly scaled to account size, not to a default demo balance
- Know whether the EA has its own maximum-loss or maximum-drawdown cutoff
Frequently asked questions
Does MixFunded allow expert advisors?
Yes, expert advisors are permitted on MixFunded evaluation and funded accounts on both MT4 and MT5. The standard drawdown and target rules for your programme still apply regardless of whether trades are placed manually or automatically.
Why is my EA attached but not trading?
The most common causes are the global AutoTrading toggle being switched off, the Allow Algo Trading or Allow live trading permission not being ticked in the EA's Common tab, or the EA's own internal conditions for a trade simply not yet being met. Check the smiley-face icon in the top corner of the chart for a quick status check.
Can I run an EA and trade manually on the same account?
Yes, and giving the EA a distinct magic number means it will not interfere with your manual positions. It is still worth tracking your combined exposure, since the account's overall equity, and therefore its drawdown, reflects both the EA's trades and your own.
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