Markets have been volatile in the first hour of trading, opening higher after the release of GDP revisions , moving lower with a disappointing business report for the Midwest, and then rebounding after a Consumer Sentiment survey beat expectations. As of 10:30, the S&P is up 0.51% to 911, the Dow has climbed 0.35% to 8432, and the Nasdaq has followed suit with a 0.42% advance to 1759. Beginning the day at 8:30 am were revisions to Q1 GDP , which came in at -5.7%. Markets were looking for a -5...