Can You Run Multiple Expert Advisors on One MT4 Account?

Can you run multiple expert advisors on one MT4 account? Once one expert advisor is running smoothly, that is usually the next question. Maybe you want a second EA on another pair, or two different strategies working side by side. The good news is that MT4 handles this well. However, a few rules decide whether multiple EAs work together or quietly get in each other’s way.

In this guide:

• The short answer
• One chart, one expert advisor
• Magic numbers
• The real risk: one shared account
• How many EAs one MT4 can run
• One MT4 terminal or several?
• Running one EA on many pairs
• Add EAs one at a time
• FAQ

The Short Answer: Can You Run Multiple Expert Advisors on One MT4 Account?

Yes. You can run as many expert advisors on one MT4 account as your computer can handle. The only hard rule is one EA per chart. So to run five EAs, you open five charts and attach one EA to each.

Running them is the easy part. Running them safely depends on three things:

• Each EA uses its own magic number, so it only manages its own trades.
• Together, the EAs do not risk more than the account can carry, because they all share one balance and one margin.
• Your computer or VPS has enough resources to keep every chart running around the clock.

How to Set Up Multiple Expert Advisors on One MT4 Account

MT4 allows only one expert advisor on each chart window. If you drag a second EA onto a chart that already has one, MT4 asks whether to replace the first. It never runs both.

That does not limit you to one EA per currency pair, though. You can open the same symbol in as many chart windows as you like. For example, two EUR/USD charts can run two different EAs, or the same EA with different settings.

To set up several EAs:

1. Open a new chart for each EA with File → New Chart, and choose the symbol.
2. Set the timeframe each EA was designed for.
3. Drag the EA from the Navigator onto its chart, check the inputs and tick Allow live trading in the Common tab.
4. Make sure the AutoTrading button in the toolbar is green. It is one switch for every EA in the terminal.
5. Check that each chart shows a smiley face next to the EA name.

If the EA does not appear in the Navigator at all, it is not installed in the right folder yet. Our guide on how to install an expert advisor into MetaTrader 4 walks through it. And if a chart shows a sad face or no trades, work through the checklist in MT4 expert advisor not trading.

Once everything is set, save the layout with File → Profiles → Save As. A saved profile restores every chart, with its EA and settings, in one click. That is useful after a reinstall or when you move to a VPS.

Magic Numbers: How Each EA Knows Which Trades Are Its Own

Every trade an EA opens carries a magic number, an ID the EA uses to recognise its own orders. When an EA decides whether to close, modify or add to a position, a well-written one only looks at trades with its own magic number.

This is the setting that matters most when you run several EAs. If two EAs use the same magic number on the same symbol, each can treat the other’s trades as its own. As a result, one EA may close a position the other just opened, move its stop-loss, or refuse to open a trade because it thinks one is already running.

So before you go live:

• Look for an input called Magic Number, MagicNumber or similar, and give each EA instance a different value.
• If you run the same EA on two charts of the same symbol, the two copies need different magic numbers too.
• If an EA has no magic number input, ask the developer how it tells its trades apart before you run it next to anything else.

Manual trades have a magic number of 0. So if you also trade by hand on the same account, make sure no EA is set to 0.

The Real Risk: Multiple Expert Advisors Share One MT4 Account

Each EA only sees its own trades. Your account, however, sees all of them at once. That is where most problems with multiple EAs start.

Margin is shared

Every open trade uses part of the same free margin. Five EAs that each look safe alone can, together, push the margin level down to the point where the broker starts closing positions. That is the stop-out. Add up the largest number of trades all your EAs can hold at once, not just the trades of one EA.

Drawdowns add up

Each EA’s backtest shows only its own drawdown. Moreover, MT4’s Strategy Tester can only test one symbol at a time, so it never shows what happens when several EAs lose together. Two EAs with a 10% maximum drawdown each can produce a much deeper combined drawdown if they lose in the same week. Plan for the combined number, using the ranges in how much drawdown is acceptable for an expert advisor.

Correlated pairs double your exposure

Some currency pairs tend to move together. For instance, EUR/USD and GBP/USD often move in the same direction, and USD/CHF often moves the opposite way. If EAs on correlated pairs all buy the US dollar at once, you effectively hold one large position, not several small ones. Spreading EAs across pairs only reduces risk when the pairs do not move as one.

The simplest protection is to lower the lot size or risk per trade on each EA when you add more of them. Then fund the account for the combined drawdown, as we explain in how much money you need to start algo trading.

Opposite trades and FIFO rules

Two EAs can easily end up buying and selling the same pair at the same time. On most MT4 accounts that is allowed, although the two positions largely cancel each other out while you still pay the spread twice. However, some brokers, notably US-regulated ones, apply no-hedging and FIFO (first in, first out) rules. On those accounts, an EA’s order may be rejected or closed in a different order than it expects. Check your broker’s rules before you run several EAs on the same pair.

How Many Expert Advisors Can One MT4 Terminal Run?

MT4 has no fixed limit on the number of EAs. In practice, the limit is your computer. Every chart uses memory and processing power, and every EA runs its code on each new price tick. MT4 is also an older 32-bit program, so a single terminal can only use a limited amount of memory, however much your computer has.

A few habits keep a busy terminal stable:

• Lower Max bars in chart in Tools → Options → Charts. Fewer stored bars means less memory per chart.
• Close charts you do not trade. Every open chart uses resources, even without an EA.
• Remove indicators the EAs do not need.
• Watch the Journal tab for “not enough memory” messages and for EAs that stop.

Above all, keep the terminal online 24 hours a day. If the computer sleeps, every EA stops at once. That is why most traders who run several EAs use a VPS, a remote computer that never switches off.

One MT4 Terminal or Several?

For most traders, one terminal with several charts is enough. However, a second MT4 installation makes sense in a few cases:

• Different accounts. One terminal can only be logged in to one account at a time. To run EAs on two accounts, install MT4 twice, in separate folders.
• Heavy EAs. If one demanding EA slows everything down, moving it to its own terminal keeps it from affecting the others.
• Isolation. If one terminal freezes or needs a restart, the EAs in the other keep running.

Each installation is a separate copy of MT4 with its own folders. So copy the EA files into each installation’s own MQL4 → Experts folder.

Running One EA on Many Pairs

Many traders do not run different EAs at all. Instead, they run one EA across several currency pairs. That works the same way: one chart per pair, one copy of the EA on each chart.

Our Free FX Robot, for example, can work on all currency pairs in parallel. We recommend the major pairs because of their small spreads: EUR/USD, GBP/USD, AUD/USD, NZD/USD, USD/JPY, USD/CHF, USD/CAD, EUR/JPY and EUR/GBP. How many of them you run should depend on your account balance and the risk you are comfortable with, not on how many charts fit on the screen.

This is also one reason two traders can report very different results from the same EA. One runs it on a single pair, another on nine. We explain this in why the same expert advisor gets different reviews.

Add Multiple Expert Advisors to One MT4 Account Gradually

The safest way to build a multi-EA setup is gradually:

1. Run the first EA alone until you know how it behaves live.
2. Add the second one on a demo account, and watch how the two interact for a few weeks.
3. Check the combined drawdown and the lowest margin level, not just each EA’s results.
4. Only then move the combination to a live account, with the lot sizes reduced to fit.

A backtest cannot show you how several EAs behave together. So the demo period is the only real test of the full setup. Our guide on how to know if an expert advisor backtest is reliable covers what single-symbol tests miss.

Frequently Asked Questions

Final Thoughts on Running Multiple Expert Advisors on One MT4 Account

Running multiple expert advisors on one MT4 account is simple: one chart per EA, AutoTrading on, and a unique magic number for each. The part that takes care is the risk. All your EAs share one balance, one margin and, often, the same market moves. So size them as one portfolio, not as separate systems.

If you want to try a multi-pair setup without paying for software, start with our Free FX Robot on a demo account. Run it on a few major pairs first, then add more once you have seen how the combined account behaves.