Robinhood Markets, Inc. is an American financial services company headquartered in Menlo Park, California, known for offering commission-free trades of stocks and exchange-traded funds via a mobile app introduced in March 2015. Robinhood is a FINRA-regulated broker-dealer, registered with the U.S. Securities and Exchange Commission, and is a member of the Securities Investor Protection Corporation. The company's revenue comes from three main sources: interest earned on customers' cash balances, selling order information to high-frequency traders (a practice for which the SEC opened an investigation into the company in September 2020) and margin lending. As of 2021, Robinhood has 31 million users.