The U.S. stock market roared back to life on Friday. After a dismal trading day on Thursday, stocks opened the Friday session in a choppy sideways pattern between 1968 and 1975 on the S&P 500 Index through much of the trading day. Then suddenly, like so many times before in the post-crisis period, stocks suddenly awoke around 1PM and rallied for the next two hours before settling into the close.