Wall Street stocks added to records early Friday, drifting higher following benign economic and trade news that have created positive momentum in recent weeks.
All three major indices closed at records on Thursday following a quiet session that saw lower volumes that are the norm in the sleepy period between Christmas and New Year's.
"The stock market is getting carried away to new record heights and in the process it is inviting accusations that it is simply getting carried away," analyst Patrick O'Hare said in a note on Briefing.com.
"That's usually about the time it gets tripped up, but for now, the good times are set to keep rolling at the open."
About 10 minutes into trading, the Dow Jones Industrial Average had risen to 28,684.27, up 0.3 percent.
The broad-based S&P 500 added 0.2 percent at 3,246.42, and the record-setting, tech-rich Nasdaq Composite Index also advanced 0.2 percent to 9,041.85, after crossing the 9,000-point threshold for the first time on Thursday.
Some analysts have warned that the market could soon see a pullback given the surge.
O'Hare, in an interview Thursday, said the ratio of US stocks valuations to earnings is currently at about a 20 percent premium to its normal level.