The Dow ended lower Monday but the S&P 500 and the Nasdaq Composite both booked record closes, supported by gains in big-capitalization technology companies and communication services. The Dow Jones Industrial Average, weighed by a decline in Boeing Co. /zigman2/quotes/208579720/composite BA -4.88% , ended solidly lower. The blue-chip index closed down 0.4% to around 34,281, on a preliminary basis. Meanwhile, the S&P 500 index /zigman2/quotes/210599714/realtime SPX -1.18% logged its 32nd record finish of 2021, up 0.2% to finish above 4,290, while the Nasdaq Composite /zigman2/quotes/210598365/realtime COMP -1.83% charged up by 1% to 14,500 and marked its 18th closing record of the year. The Nasdaq Composite's moves were led by gains in Amazon.com Inc. [: AMZN], Nvidia Corp. /zigman2/quotes/200467500/composite NVDA -3.79% and Tesla Inc. /zigman2/quotes/203558040/composite TSLA -4.35% .