Brad Katsuyama has racked up oceans of newspaper ink since being propelled into the public spotlight as the protagonist of Michael Lewis's book on high-frequency trading, Flash Boys. The 38-year-old co-founder and chief executive of IEX, an exchange with a 'speed bump' designed to slow down lightning-fast traders on behalf of longer-term investors, won U.S. regulatory approval in June. In this special edition of Odd Lots, Katsuyama speaks with Bloomberg View Columnist Matt Levine about the next big steps in stock market structure.