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. About 20 minutes into trade, the Dow Jones Industrial Average rose 50.70 points (0.32 percent) to 16,012.40. The broad-based S&P 500 also soared to a new all-time high, edging above 1,800 for the first time, before retreating slightly to 1,799.42, up 1.24 (0.07 percent). The biggest gainer in the Dow was Boeing (+3.2 percent), which together with rival Airbus, announced more than $140 billion in new orders at the Dubai Airshow over the weekend.