The U.S. Securities and Exchange Commission (SEC) Thursday charged stock trading app Robinhood Financial with misleading customers on the source of its revenue and failing to secure them the best possible trades.

"The order finds that Robinhood provided inferior trade prices that in aggregate deprived customers of $34.1 million even after taking into account the savings from not paying a commission," the SEC said. Robinhood settled the SEC charges with a $65 million penalty.