Look out for a low drawdown rate. This is a measure of decline and reduction of capital, and although high drawdowns can mean higher gains, they can also cause an account to go broke.
The best robots are thoroughly tested, against real tick data, variable spreads and real slippage. This backtesting should be available for you to view before you purchase, and real-time data from third party sites like myfxbook can help inform you how the robot is performing today.
Be wary of product reviews from unverified sources. The developers will only want to show positive reviews, and people who have lost money while using a particular robot will be likely to give it a bad review. Compare reviews from genuine users before investing.
Use a demo account. Before deciding to use a robot, try it in a test environment first. This will allow you to see how it performs under test conditions – although, be aware that test conditions can not fully simulate a real trade situation. If the robot you are considering does not offer a demo or test version, it might be too risky to invest capital in it. During the demo, you can see what settings and parameters are used by the robot too, and get used to how it works.
Make sure that you remember all robots will require some supervision. System failures, problems with internet signals and catastrophic loss can happen, so although these robots are designed to work autonomously, you will have to intervene at some point.
The most important thing to remember when choosing a product is that there are no guarantees when it comes to gains from forex and cryptocurrency trading. Products that guarantee financial gains without any form of money-back guarantee should be avoided; many of the most popular robots offer at least 60 days trading and a full refund, which makes them seem less likely to be a scam.