Robinhood is a commission-free trading app that popularized zero-fee stock and options trading for retail investors, building a customer base skewed younger and more mobile-first than traditional brokerages. Rather than charging trading commissions directly, Robinhood earns much of its revenue by routing customer orders to market makers who pay for that order flow, along with interest earned on customer cash balances and margin lending. The company has expanded beyond its original stock trading app into cryptocurrency trading, retirement accounts and a subscription tier offering additional features, broadening its revenue beyond pure trading activity. Robinhood's business is closely tied to retail trading volumes and market volatility, since trading activity, and the payment-for-order-flow revenue tied to it, tends to rise when markets are moving sharply and investors are most active.