Robinhood is a zero-commission stock trading app that aims to make trading accessible to more people, especially those with lower incomes who found commissions to be prohibitive. It was founded in 2014 by two Stanford alumni and has since grown significantly, reaching over 4 million customers in 2019 and an estimated valuation of $7.6 billion. Robinhood makes money through interest on idle cash balances in accounts, fees from its premium Robinhood Gold membership, and rebates from routing customer trades to high-frequency trading firms.