Founded in 2013 by Vlad Tenev and Baiju Bhatt, Robinhood is an online broker known for its groundbreaking monetization of a practice called payment for order flow. By optimizing revenues from selling its customers’ orders to various exchanges, Robinhood  was able to pass the transaction costs to the exchanges, rather than the retail trader. That meant that customers could trade commission-free. The popularity of Robinhood’s business model grew rapidly after its founding, and eventually all the major brokers took on the same practice of offering commission-free trades.