[throwaway9d0291]

This phenomenon is also exploited in unregulated areas like forex trading robots.

A scammer will set up a bunch of systems trading some relatively small amount of real money and let them do their thing. After some time, some number of their robots will have actually made a decent amount of money, at which point the scammer will start offering the trading robot for sale on various marketplaces. Hundreds of people buy the robot and quickly find that it doesn't really make money.