Choosing a Broker to Run an EA On
An EA does not care about a broker's marketing. It cares about six or seven numbers in the contract specification, and about whether the account type allows the strategy to exist at all. Here is the list to work through before you deposit, in the order that can disqualify a broker fastest.
Check these before anything else
Two questions can rule a broker out completely, so ask them first.
Do they offer a hedging account on MT5? If the EA is a grid, a basket or anything that holds both directions at once, a netting account cannot run it. Most brokers offer both, but not all, and you cannot convert an account after opening it. The mechanics are in hedging vs netting accounts.
Do they allow automated trading on that account type? Almost all do, but a handful restrict EAs on certain promotional or swap-free accounts. It is written in the account terms, and support will answer it in one line.
The numbers, and where to read them
All of these live in one place: Market Watch, right click, Symbols, pick the pair, read the specification. Do it on a demo of the exact account type you intend to open.
Spread, measured rather than advertised
Advertised spreads are averages or best cases. Watch the pair you will trade for a full day on a demo, including the daily rollover, and note the worst figure. That number, not the advertised one, is what your EA will meet at 00:00 server time.
Commission, converted into pips
Raw accounts charge per lot instead of widening the spread. Convert it so the two are comparable: on EURUSD, $7 per lot round turn is about 0.7 pips. Only then can you compare a raw account with a standard one.
Stops level
The minimum distance a stop loss or take profit may sit from price. If an EA places a take profit closer than this, the order is rejected outright with invalid stops, and the EA looks broken while the broker is simply refusing.
A stop level of 0 is ideal. Anything above about 20 points deserves a look at whether the EA's default take profit clears it.
Minimum lot and lot step
0.01 with a 0.01 step gives an EA room to size sensibly on a small account. A minimum of 0.1 on gold or indices means the smallest possible position may already be too large for your balance.
Swap
Charged nightly, tripled one day a week. For a strategy that holds positions for days, swap can quietly consume a meaningful share of the profit, and it is often the difference between a backtest and a live result.
Contract size and tick value
Worth a glance on anything that is not a currency pair. Gold, indices and crypto CFDs vary enormously between brokers, and a lot on one is not a lot on another.
Execution: the part the specification does not tell you
Two brokers can show identical spreads and behave completely differently when the market moves.
Market execution fills your order at whatever price is available, which is what you want for an EA. Instant execution can come back with a requote, and an EA that is not written to handle one may simply skip the trade.
The only reliable test is a small live run. Place a handful of trades at the size the EA would use and compare the fill price against the price requested. That difference is your slippage, and no demo will show it to you.
Server time, which decides your trading hours
An EA's StartHour and StopHour run on the broker's server clock, not yours. Brokers sit on different offsets, commonly GMT+2 or GMT+3, and the offset shifts with daylight saving.
Read the clock in Market Watch before setting any trading window. A strategy tuned for the London session on a GMT+2 broker is trading a different session on a GMT+3 one, with the same numbers in the settings.
Practical checks worth five minutes
- Does a demo account exist on the same server type? If you can only get a generic demo, you cannot test any of the above properly.
- Is MT5 build up to date? Brokers occasionally lag, and an old build can behave differently.
- What are the weekend and holiday hours? These vary per symbol group and explain a lot of "why did it not trade" questions.
- How many accounts can you open? Running a demo beside your live account is how you test settings changes safely.
- Withdrawal terms, in writing. Not an EA question, but the one people wish they had asked.
What does not matter as much as the marketing suggests
Ultra-low latency. It matters for a scalper working in seconds. For a strategy deciding on closed hourly bars, with pending orders already sitting at the broker, anything under about 100ms is comfortable. Uptime matters far more, which is the subject of do you need a VPS.
Huge leverage. 1:1000 does not improve a strategy. It removes a limit that was protecting you from sizing too large.
Bonuses. Deposit bonuses usually carry volume conditions that an EA will meet accidentally and expensively.
Before the first live trade
- Open a demo on the exact account type and copy the symbol specification into a note.
- Add spread and commission together, in pips, for your pair.
- Check the EA's default take profit clears the stops level.
- Work out the margin for the largest position set the EA can open, at that leverage.
- Run live at the minimum size for a week and measure slippage.
If you are sizing the first live account, the lot size calculator starts from the balance rather than from what the account could theoretically carry.