In the last quarter of 2012, for example, the brokerage TD Ameritrade sent all nonmarketable customer orders those that cant be completed immediately based on the market price to the one exchange that paid the highest rebate. In the first quarter of 2014, it sent nonmarketable orders to two venues that paid the highest rebates.
Senator Carl Levin, the subcommittee chairman, rightly called it a frankly pretty incredible coincidence that the firms judgment on best execution for tens of millions of customers had invariably led it to use the venues that paid the highest rebates. Under questioning, Steven Quirk, an executive of TD Ameritrade, conceded that in the trades cited by Mr. Levin the firm had virtually always used exchanges that paid the most. He also estimated that the firm made $80 million last year from maker-taker rebates.
Meanwhile, many brokerages promote their low trading costs. But the fees to trade stocks do not include the hidden costs that are incurred when investors dont get the best price. A study from 2012 estimated that rebates cost individual investors, mutual funds and pension funds as much as $5 billion a year.