All of the major brokerage firms — Charles Schwab, Interactive Brokers, TD Ameritrade and most recently Fidelity — dropped their commission fees to zero this month, which means these companies will no longer be charging clients a fee per transaction. Amke, how will they make their money? The broker can sell to a wholesale market maker, like Citadel Securities or Virtu Financials. These market makers buy or sell a stock at publicly quoted prices and actually pay brokerage firms for routing a trade through. The difference in the price is called the spread. In a structure how online brokerage companies make money the broker sells the order flow to a market maker, onilne bounty is split by the broker and the market maker. Selling order flow has become more lucrative for brokers. The big firms followed suit in cutting their fees to keep their clients from running to Robinhood, or other fee-less platforms. This practice has drawn scrutiny from regulators globally because it creates an incent...