...market's wild swings. While investors hold their collective breath at each major undulation, day traders thrive on it. Andy Friis, 26, says he lost $50,000 in Thursday's market rout but bet correctly on Friday morning's downturn and made...

...market's wild swings. While investors hold their collective breath at each major undulation, day traders thrive on it. Andy Friis, 26, says he lost $50,000 in Thursday's market rout, but had bet correctly on Friday morning's downturn and...