SEC decision on new stock exchange imminent

IEX’s solution, Macey said, is to put a kind of speed bump along the motorcyclists' or the high-speed traders’ paths so they can’t make such a maneuver. 

“So they're not going to be at a distinct advantage they might be on many of the other current exchanges and other venues,” said Tyler Gellasch, executive director of Healthy Markets Association, a group of institutional investors. 

IEX is already operating as a private trading venue. It's not clear how much influence it would have as a public stock exchange. But Gellasch said brokers would be forced to route trades through IEX in its public form — if it offers the best prices.

Listen to the full story on NPR's Marketplace here.