The Nasdaq Composite Index has pushed though the 4000 mark for first time in 13 years., led by non-technology stocks.
Healthcare and consumer stocks increasingly comprise the bulk of the index, which has climbed 33% this year, a full 10 percentage-point more than the blue chip Dow Jones Industrial Average.
In trading on Wall Street, the Nasdaq has risen as high as 4007. Despite the recent gains, though, the Nasdaq remains a full 25% below its all-time high. It peaked at 5048.62 on March 10, 2000.
This morning, the Dow is up 10 points, or 0.1%, to 16,075 after passing through that milestone for the first time last week.
On Friday, it rose 55 points, or 0.3%, to a sixth record high close in eight sessions. The Dow also posted a seventh-straight weekly gain, the longest such stretch since January 2011.
The broader S&P 500 closed above 1800 on Friday for the first time to post its 37th record high close of the year. It is trading above that level this morning.
Market sentiment is favouring consumer and healthcare stocks after oil prices plummeted on the weekend agreement to reduce sanctions on Iran in exchange for a curb on its nuclear programme.
This will make it easier for Iran, one of the world's largest producers, to export some of its crude oil to international markets.
January crude-oil futures have dropped 1.3% to $US93.63 a barrel in New York trading.