The Dow topped 16,000 for the first time in opening trade Monday, fueled by a wave of new Boeing plane orders and continued positive investor sentiment for stocks. Four minutes into trade, the Dow Jones Industrial Average rose 62.88 points (0.39 percent) to 16,024.58. The broad-based S&P 500 nudged above the 1,800 mark at 1,801.97, up 3.79 (0.21 percent).