Stocks moved to the upside at the start of trading on Monday but quickly gave back ground early in the session. The major averages pulled back well off their early highs and spent much of the rest of the day lingering near the unchanged line.The major averages eventually ended the day modestly lower. While the tech-heavy Nasdaq slid 137.76 points or 0.6 percent to 23,057.41, the S&P 500 dipped 10.90 points or 0.2 percent to 6,816.51 and the Dow edged down 41.49 points or 0.1 percent at 48,416.56.The initia ...