Robinhood is a commission-free stock trading platform that aims to make investing easy and accessible for young people. It has grown rapidly since its 2015 launch, reaching over 7 million users in 2018 through its mobile-focused design and social growth incentives. While Robinhood does not directly charge commissions, it generates revenue through interest on customer cash balances, premium subscriptions, and selling order flow. The company continues to expand its offerings like options and cryptocurrency trading as it works towards an IPO.