An old Wall Street maxim says the "dumb money" buys in the morning and the "smart money" buys late in the trading day. But statistics show the opposite is true. According to Bespoke Investment group, the first half hour of the trading day is anything but "amateur hour." In fact, it's the best time to buy and sell. Bespoke's report shows that if an investor bought the S&P 500 at the previous day's close and then sold it at 10 a.m., every single trading day since 1983, a $100 investment would be worth $949 today, making it the single best portion of the trading day. (Bespoke counted 9:30 to 10 a.m. as a full hour so ... (full story)