In June 2007, Brad Katsuyama noticed a problem on Wall Street. Working as an equity trader for the Royal Bank of Canada, he started to see markets drying up as soon as he placed an order, almost as if someone was beating him to the punch. Michael Lewis new book Flash Boys (excerpted in The New York Times Magazine) details the long hunt that followed, as Katsuyama tracks down the intricate mechanisms that let high-frequency traders construct a shadow market beyond the reach of everyday traders.