Running Multiple EAs at Once โ MagicNumber and Interference Prevention
Last updated: 2026-05-20 | Estimated reading time: 14 min
Running multiple EAs together can diversify risk and smooth out performance. However, incorrect configuration can cause EAs to interfere with one another, leading to unexpected losses. This article covers the practical points you need to run multiple EAs safely at the same time.
Contents
Benefits of running multiple EAs simultaneously
Relying on a single EA means the entire account falls into drawdown whenever that EA enters a difficult market phase. Combining multiple EAs with different market tendencies allows one EA to hold its own while another is underperforming, resulting in a smoother equity curve.
To maximize this effect, it is important to select EAs with low correlation. Simply stacking EAs on the same currency pair with the same strategy provides no real diversification. Combine different currency pairs and different strategy types โ for example, trend-following alongside mean-reversion.
The role of MagicNumber
MagicNumber is a number used by an EA to identify the positions it has opened. Each position carries this number, and an EA only operates on positions that carry its own MagicNumber.
When multiple EAs run on the same account, as long as each EA has a different MagicNumber, they will not interfere with each other's positions. If two EAs share the same number, however, one EA may accidentally close a position opened by the other.
Preventing EAs from interfering with each other
Beyond MagicNumber, keep the following in mind when running multiple EAs.
Give every EA a unique MagicNumber
This is the most important rule. EAs from this site ship with a unique number pre-assigned. If you change it yourself, make sure there are no duplicates.
Avoid running multiple EAs on the same symbol
Running more than one EA on the same symbol can cause one EA's positions to influence the other's logic. The general rule is one EA per symbol.
Keep to one EA per chart
MT5 only allows one EA per chart. Open a separate chart for each EA.
Check for unintended hedging
If one EA is long and another EA is short on the same symbol, the account is in a net-hedged state. Avoid unintended hedging.
Managing combined risk
The most commonly overlooked aspect of running multiple EAs is combined risk. If each EA is set to 1% risk, the moment three EAs all enter at the same time the account's total risk is 3%.
Furthermore, highly correlated EAs tend to enter in the same direction at the same time, which inflates combined risk even further. The more EAs you add, the lower each individual EA's risk percentage must be.
| No. of EAs | Risk per EA (guideline) | Combined risk (guideline) |
|---|---|---|
| 1 | 1.0% | 1.0% |
| 2โ3 | 0.5โ0.7% | approx. 1.5โ2.0% |
| 4โ6 | 0.3โ0.5% | approx. 2.0โ2.5% |
| 7 or more | 0.2โ0.3% | keep below 2.5% |
How many EAs can one MT5 instance handle?
MT5 itself can run many EAs concurrently, but the practical limit is determined by your VPS or PC specifications. Each additional EA means another chart and more indicator calculations, which consume memory and CPU.
A VPS with 2 GB of RAM can generally handle 3โ5 EAs stably; 4 GB allows roughly 5โ10. EAs with heavy compounding calculations or those that use many indicators consume more resources.
๐ Learn how to combine EAs effectively
The effectiveness of running multiple EAs depends on which ones you pair together. The portfolio strategy article explains how to build a combination.
Read the portfolio strategy guide โ