Henry Blodget has assembled some nice historical charts here. However, while the charts give perspective and show definitively how tough buy and hold can be — please don’t take any predictive value from them as to future S&P 500 moves. I don’t think that was Blodget’s intent, but it is easy to see where some might draw that inference. Don’t. Follow the trend. “Chart reading” (whatever that might mean to whoever exactly) is not what great traders do.