NEW YORK (AFP) - Tech shares led US stocks higher Monday, with Apple surging ahead of a new iPhone launch as investors shrugged off the stalemate over US stimulus talks in Washington.

The tech-rich Nasdaq Composite Index jumped 2.6 per cent to 11,876.26.

The Dow Jones Industrial Average advanced 0.9 per cent to 28,837.52, while the broad-based S&P 500 climbed 1.6 per cent to 3,534.22.

Apple soared 6.4 per cent ahead of a much-anticipated event where the tech giant is expected to unveil its 5G-capable iPhone 12 line-up.

Wedbush Securities called the new iPhone "Apple's most important product cycle since the iPhone 6 in 2014," with demand by Chinese consumers to upgrade to the phone expected to be strong.

Other large technology companies such as Facebook and Google parent Alphabet also posted big gains, although there was no obvious catalyst for the move, said Art Hogan, chief market strategist at National Securities.

The latest maneuverings by the White House on fiscal stimulus suggests significant difficulty in reaching an agreement before the November 3 election, but investors are becoming more confident of a larger deal down the road.

Hogan said many investors believe the Democrats will retake the White House under former Vice President Joe Biden, and that Biden's widening lead in the polls means a contested election has become less likely.

"That narrative has shifted and Wall Street seems to be warming to a blue wave," Hogan said, adding that investors now anticipate a larger stimulus package after the election.