Stock market today: Dow crosses 49,000, S&P 500 jumps to new high in record-setting start to year

Group 1 - US stocks reached record highs, with the S&P 500 and Nasdaq Composite both rising by 0.6%, and the Dow Jones Industrial Average climbing 1% to close above 49,000 for the first time [1] - Nvidia and AMD presented their AI roadmaps at CES, with Nvidia launching the Vera Rubin AI superchip platform and AMD showcasing its Helios system [2] - Tech stocks such as Amazon, Micron, and Broadcom saw notable gains [3] Group 2 - The final reading of S&P Global's Services PMI for December indicated the US services sector grew at its slowest pace in eight months [3] - The recent shutdown has complicated the assessment of the Federal Reserve's interest rate decisions, with Chair Jerome Powell indicating a cautious approach until labor market data is clearer [4] - Copper prices surged above $13,000 a ton for the first time, driven by concerns over potential Trump tariffs and resulting stockpiles in the US [5]