"Federal officials said that between 2015 and 2018 the company only partially explained on its online FAQ page how it makes money, omitting details about its largest revenue source — trades. Robinhood takes a user's stock order and sells it to a larger trading firm that executes the trade, a process known as "payment for order flow," the SEC order states."
The SEC disagrees
https://www.cbsnews.com/news/robinhood-sec-fine-65-million/
"Federal officials said that between 2015 and 2018 the company only partially explained on its online FAQ page how it makes money, omitting details about its largest revenue source — trades. Robinhood takes a user's stock order and sells it to a larger trading firm that executes the trade, a process known as "payment for order flow," the SEC order states."