Is it a great Autonomous FX Trading Strategy or you are just fooling yourself

There are many practitioners that create software to buy and sell financial assets in an autonomous way. There are some digital platforms that allow the development, test and deployment of trading agents (or robots) in simulated or real markets. Some of these work focus on very short horizons of investment, while others deal with longer periods. The spectrum of used AI techniques in finance field is wide. There are many cases, where the developers are successful in creating robots with great performance in historical price series (so called backtesting). Furthermore, some platforms make available thousands of robots that [allegedly] are able to be profitable in real markets. These strategies may be created with some simple idea or using complex machine learning schemes. Nevertheless, when they are used in real markets or with data not used in their training or evaluation frequently they present very poor performance. In this paper, we propose a method for testing Foreign Exchange (FX) trading strategies that can provide realistic expectations about strategy's performance. This method addresses many pitfalls that can fool even experience practitioners and researchers. We present the results of applying such method in several famous autonomous strategies in many different financial assets. Analyzing these results, we can realize that it is very hard to build a reliable strategy and many published strategies are far from being reliable vehicles of investment. These facts can be maliciously used by those who try to sell such robots, by advertising such great (and non repetitive) results, while hiding the bad but meaningful results. The proposed method can be used to select among potential robots, establishes minimal periods and requirements for the test executions. In this way, the method helps to tell if you really have a great trading strategy or you are just fooling yourself.