The S&P 500 closed at a record 7,818.93 on Tuesday, its first finish above 7,800, rising 0.6 percent. The Nasdaq Composite gained 0.5 percent to 27,599.79, extending its record run to a second session. The Dow Jones Industrial Average added 0.5 percent to 51,521.28.

S&P 500 futures inched 0.1 percent higher to 7,880.75 by 20:03 ET. Nasdaq 100 futures traded flat at 31,493.25, while Dow Jones futures were muted at 51,827.0.

AI-related semiconductor stocks led the rally. Advanced Micro Devices (NASDAQ:AMD) and Marvell Technology (NASDAQ:MRVL) gained on strong optimism for chip demand in artificial intelligence infrastructure. Nvidia remained near a $6 trillion market valuation.

Constellation Energy (NASDAQ:CEG) jumped after announcing a long-term electricity deal with Alphabet's Google. The agreement signals investor focus on the power infrastructure required to support expanding data centers.

Treasury yields retreated from recent highs, supporting equities. The 10-year Treasury yield ended Tuesday around 5.28 percent, down approximately 3 basis points from Monday's 5.35 percent—its highest level since April 2002. The two-year yield fell to about 4.80 percent.

Interest-rate futures currently price an approximate 80 percent probability of no change at the Fed's October meeting, a sharp reversal from expectations a week earlier following softer employment and inflation data. Investors are awaiting the Federal Reserve's September meeting minutes, scheduled for release Wednesday, which will detail policymakers' debate on further rate increases.

Oil prices eased from recent highs. Brent crude remained around $100 a barrel, with continued Middle Eastern shipments preventing a sharper supply shock despite the prolonged conflict around the Strait of Hormuz.

Corporate earnings season begins next week, with third-quarter results expected to provide insight into company performance and economic conditions.