IEX Group Inc. Chief Executive Officer Brad Katsuyama

IEX Group Inc. Chief Executive Officer Brad Katsuyama

Chris Goodney/Bloomberg

IEX Group Inc. Chief Executive Officer Brad Katsuyama speaks during an interview in New York. Gathering users is one of the challenges faced by Brad Katsuyama’s alternative venue, which uses time delays to cordon itself off from strategies it deems exploitative.