IEX’s transition from a private trading venue, known as a dark pool, with a less than 2 per cent share of daily trading to a fully regulated exchange may also reflect changes in how US exchanges and the broader market operate. “We are ready,” Bradley Katsuyama told the FT at IEX’s offices two weeks before the launch. Looking happy and relaxed in the classic sleeveless fleece vest of a trader over a button down-shirt with the sleeves rolled up, the IEX chief said he feels a lot less stress now. The application process lasted months and was marked by a bitter debate among industry participants about whether IEX’s speed bump, designed to slow trading, was permissible under market rules.

http://www.ft.com/cms/s/0/a0854f32-62ae-11e6-a08a-c7ac04ef00aa.html#axzz4HbPuAA3D