The S&P 500 finished at a fresh record on Tuesday as US stocks shook off a lacklustre open to move higher ahead of a Federal Reserve decision.

All three major indices advanced, with the S&P 500 at 5,178, up 0.6 percent, topping a record set a week ago.

The Dow Jones jumped 0.8 percent to 39,110, while the Nasdaq climbed 0.4 percent to 16,166.

Major indices had opened mostly lower after the Bank of Japan finally pivoted its monetary policy, becoming the last major central bank to lift interest rates.

The decision came ahead of Wednesday's announcement by the Fed.

While the US central bank is widely expected to keep interest rates unchanged, its decision will be analysed as far as setting expectations for future interest rate cuts.

"The stocks have one eye on the bond market but probably more eyes on Nvidia and all AI things," said Karl Haeling of LBBW as investors digested Nvidia's latest announcement about new artificial intelligence offerings.

"That market doesn't go down for very long," Haeling said of Nvidia, which finished up 1.1 percent after starting the day lower.

Among other individual stocks, Nordstrom surged 9.4 percent following a report the department store chain could go private. (AFP)