[Development Log] What is "Portfolio Management" by combining multiple EAs? Explanation of benefits and cautions

When trading with FX automated trading (EA), once you find a superb logic, you tend to want to continue operating with that EA alone. However, in reality there is a concept called "multi-strategy portfolio trading" that combines multiple EAs with different characteristics, and adopting this approach may help improve operational stability. This time, we will整理 the basics of this concept and the key points to keep in mind when implementing it.

■ Basic ideas of multi-strategy and portfolio operation

Multi-strategy operation can be simply described as the idea of “not entrusting all assets to one EA, but dividing roles among several EAs.” In the world of stock investing there is the idea of “not concentrating on a single asset, but diversifying across multiple assets,” and this is a close image to applying that concept to FX automated trading.

For example, by combining a logic that excels in trending markets with a logic that excels in ranging markets, there is a higher likelihood that one of the EAs will function well in any market environment. Combining EAs with different currency pairs and timeframes is also a commonly used technique. Specifically, a structure such as a swing-type EA that follows trends on daily to weekly charts, an EA that targets reversals in ranging markets on about a 1-hour chart, and a scalping-type EA that operates only during highly volatile times can be contemplated. The core of this concept is that, as market conditions change, the EA with a specialty shifts in and out of operation, keeping at least one that can produce results at all times.

■ Benefits gained by combining

The biggest benefit of combining multiple strategies is that the asset curve tends to become smoother. When running with a single EA, if the market environment that the EA struggles with occurs, the entire asset can stagnate unchanged.

However, by combining EAs with different characteristics, while one is stagnating, another may be functioning. As a result, the drawdown of the portfolio as a whole tends to be smaller than when viewed only at the level of individual EAs, and a stable asset curve is more likely. The idea of “not entrusting everything to one EA” provides not only financial security but also psychological reassurance. Even in situations where a single EA is carrying large unrealized losses, if other EAs are accumulating profits, the total account can remain calm and observe the situation.

■ Three pitfalls that are easy to overlook

The first is misjudging correlations. On the surface they may seem to use different logic, but the rationale for entries may be similar, leading to losses in the same direction at the same timing. This means you are effectively bearing the same risk twice or thrice, despite diversifying. Do not judge merely by EA names or descriptions; it is essential to verify actual price movement correlations. Specifically, lay out each EA’s daily profit and loss to overlay asset curves, or calculate correlation coefficients of profit and loss data to check quantitatively without being misled by appearances.

The second is the complexity of资金管理 (fund management). When multiple EAs are running simultaneously, each may calculate lot sizes independently, potentially making the overall margin maintenance rate more stringent than expected. Even if each EA performs proper risk management, the overall account risk management must be checked from another perspective. In particular, when multiple EAs hold positions on the same currency pair simultaneously, unexpected unrealized losses can accumulate, so caution is required.

The third is the burden of management. As the number of active EAs increases, the amount of work to understand each behavior and check for anomalies also increases. If the number becomes too large, you may fail to grasp how each EA is operating, which defeats the purpose. The abnormality-detection mechanisms discussed in previous articles are not irrelevant; you must also have these mechanisms for the number of EAs. Furthermore, if each EA operates on different brokers or VPS environments, you must also pay attention to environment-specific troubles (connection drops, spread widening, etc.), and management costs do not rise simply in proportion to the number of EAs but at an even faster rate.

■ Three points for effective combination

・ beforehand, verify the price movement correlation between the combined logics
・decide capital allocation rules in a way that allows you to oversee the overall account margin maintenance rate
・limit the manageable number of EAs (as a guideline, about 3–5) and regularly check their operating status
・not only review each EA’s verification report but also regularly examine actual performance data after deployment to ensure it does not diverge from the expected correlations and performance

“Simply increasing the number of EAs will make it safer” is not always true; it seems that the essence of portfolio operation lies in combining logics with different characteristics within a reasonable range. When capital is small, a realistic option is not to force multiple EAs to operate, but to first grasp the operating feel with 1–2 EAs, and gradually increase the number after capital and experience have accumulated.

■ Summary

Combining multiple EAs can be a powerful means to stabilize the asset curve depending on the design. However, simply increasing the number without checking correlations can lead to risks not being distributed, but rather to an uncontrollable state. The key is the mindset of “not relying on a single logic too much” and the attitude of “carefully designing the combination.” Only with both can you maximize the benefits of multi-strategy operations. For those already running multiple EAs, consider reviewing the correlations among them.

? If you have questions about the market or the logic, Semura_Lab Yorozu So-danjo (General Consultation) also accepts inquiries.
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