Wall Street stocks surged to fresh records on Wednesday, extending a post-election rally on optimism about more interest rate cuts and an artificial intelligence boom after strong Salesforce results.

All three major indices scored records, led by the Dow Jones, which finished above 45,000 for the first time.

"The market at this point is looking for excuses to go up, and there's not really anything that might work against that narrative," said Steve Sosnick of Interactive Brokers.

"Over the last couple of days, it's managed to ignore all sorts of inconvenient things," Sosnick said of the market's shrugging response to political upheaval in France and South Korea.

The Dow Jones finished up 0.7 percent at 45,014.

The S&P 500 gained 0.6 percent to 6,086, its fourth straight record, while the Nasdaq jumped 1.3 percent to 19,735, its third straight record.

Wednesday's gains came after payroll firm ADP said US private-sector hiring in November came in at a lower-than-expected 146,000 jobs, while a survey from the Institute for Supply Management showed weaker sentiment than expected in the services sector.

However, the lacklustre data boosts expectations that the Federal Reserve will cut interest rates later this month.

At a New York conference, Federal Reserve Chair Jerome Powell refrained from tipping his hand, but he "didn't say anything that would scare the market," said Briefing.com analyst Patrick O'Hare.

O'Hare noted that Wednesday's gains were led by large tech names such as Nvidia and Microsoft, which are major AI players.

The boost followed strong results from Salesforce, which was the biggest gainer in the Dow with an 11 percent jump. (AFP)