NEW YORK (AFP) - Wall Street scored another positive finish on Wednesday (Aug 30) as rosy economic figures boosted shares in light pre-holiday trading, while tech stocks surged.

Apple hit a record share price which helped lift the Nasdaq to robust gains amid rising anticipation for the next-generation iPhone 8.

And President Donald Trump repeated his pledge to reduce corporate taxes to as low as 15 per cent, a campaign promise that is confronting the reality of a bitterly divided Congress working under pressure.

The blue-chip Dow Jones Industrial Average gained 0.1 per cent to end the late-summer session at 21,892.08.

The broader S&P 500 rose 0.5 per cent to 2,457.57 - a four-day winning streak - while the Nasdaq rose slightly more than 1 per cent, to hit 6,368.31, putting that index up for three days in row.

Adam Sarhan of 50 Park Investments called the gains a "relief rally." Investors were comforted that Washington offered a more measured response to this week's nuclear provocations from North Korea.

"The market is cautiously optimistic but remains cognizant of the fact that we are on bad headline away from a nasty decline," he said.

Stocks also were helped by the healthy economic data as the Commerce Department reported the US economy grew far faster in the second quarter than originally estimated, moving growth up to an annualised rate of 3 per cent - hitting a target set by the White House.

The payrolls firm ADP also reported robust private job creation for the month with 237,000 new positions added.

On the Nasdaq, Netflix surged 3.5 per cent while Apple added 0.3 per cent to hit a fresh all-time high of US$163.35.

With a fifth of US refinery capacity off line due to Hurricane Harvey, oil stocks added to their recent losses, with Chevron finishing down 0.1 per cent, ExxonMobil losing 0.4 per cent, and Royal Dutch Shell dropping 0.5 per cent.