After coming under pressure early in the session, stocks saw continued weakness throughout much of the trading day on Thursday. The major averages more than offset the gains posted during Wednesday's session, falling to their lowest closing levels in two weeks.The major averages moved to the downside going into close, ending the day just off their lows of the session. The Nasdaq tumbled 445.80 points or 1.9 percent to 23,053.99, the S&P 500 slumped 75.97 points or 1.1 percent to 6,720.32 and the Dow slid 3 ...