Foreign Exchange Autotrading Robots do exist and are used by certain traders under certain circumstances, but they are very specialised tools for dealing with certain markets in certain conditions. MT4 (MetaTrader 4) ForEx traders use a programming language called MQL4 to develop trading algorithms known as 'bots' or 'robots' that can trade between shares under certain circumstances but these circumstances are monitored carefully and the bots are restricted in various ways by price, currency and timings. This prevents the robots from losing huge sums of money which they could easily do if left unmonitored.
MT5 users can trade CFDs, stock and ForEx and can write bots using MQL5 which is an updated version of MQL4. CFDs and Stocks along with different types of hedging and purchasing offer more possibilities than were available with MT4 but CFDs are a highly speculative form of trading and are not regulated or permitted with the United States.
Both types of software allow for demo accounts to be opened but do be warned, the majority of all retail accounts (80%) lose money and continue to. Most traders of CFDs and ForEx never recover what they put in and remain addicted to a cruel master. They have to pay for the 20% that win.
If you see an advert or website claiming that the robot always wins or that you push an 'autotrade' button and await wealth to arrive is a scam.
Any website offering autotrading that deal in Cryptocurrencies is a scam.