Running Commentary on the SP Movements., page-11288

http://www.nasdaq.com/investing/profit-day-trader.stm

"The long list of successful investors that have become legends in their own time does not include a single individual that built his or her reputation by day trading. Even Michael Steinhardt, who made his fortune trading in time horizons ranging from 30 minutes to 30 days, claimed to take a long-term perspective on his investment decisions. From an economic perspective, many professional money managers and financial advisors shy away from day trading, arguing that the reward simply does not justify the risk."