The S&P 500 and Nasdaq indexes closed at record highs on Wednesday, powered mainly by technology stocks as markets digested economic data that could support a much-expected start to the Federal Reserve's policy easing cycle.

The S&P 500 gained 1.2 percent to end at 5,354, the Nasdaq Composite gained just under two percent to 17,187. The Dow Jones Industrial Average rose 0.3 percent to 38,807.

The May private payrolls report on Wednesday became the latest data to suggest an easing in labour market tightness that could propel the Fed to begin cutting rates this year. A report on Tuesday showed job openings fell in April to the fewest in more than three years.

"We're seeing the economic data starting to ease up a little bit and the repercussions for that is that you're seeing the pressure on rates come off the boil a little bit mixed in with the potential for weaker economic data, which is a pretty good recipe for the bond market," said Jack Janasiewicz, a portfolio manager at Natixis Investment Managers Solutions in Boston.

Traders now see a nearly 69 percent chance of a September rate reduction, according to the CME's FedWatch tool. Expectations had hovered around 50 percent last week.

US 10-year Treasury yields fell to a two-month low on Wednesday after a report pointed to weaker-than-expected job growth ahead of Friday's highly anticipated government employment report for May.

Chip stocks leapt, buoyed by gains to Nvidia and Taiwan Semiconductor Manufacturing, which both touched record highs.

Hewlett Packard Enterprise rose after forecasting third-quarter revenue above Street expectations, helped by upbeat demand for its AI servers.

Intel gained after buyout firm Apollo Global Management agreed to purchase 49 percent for US$11 billion in a joint venture related to the chipmaker's Ireland manufacturing unit. (Reuters)