when i read about the on-line traders, i am reminded of the '50s sf classic by pohl & kornbluth, gladiator-at-law. though the book's spot -on extrapolation of that decade's absurdities mainly bashes lawyers and professional sports and giant corportions, it posits a stock market where shares are bought and sold on racetrack style parimutual machines. in g-a-l, they are located in a central bourse not hundreds of thousands of home offices, but otherwise it seems as prescient as anything else in the book.