The Dow Jones Industrial Average rose 9.46 points (0.08 per cent) to 12,463.00 in early trade, after closing near a three-year high Wednesday.
The tech-rich Nasdaq Composite gained 12.35 points (0.44 per cent) to 2,814.86, while the broad-market S&P 500-stock index climbed 4.52 points (0.34 per cent) to 1,334.88.
"The summation on the latest batch of earnings reports reads very much like the one offered yesterday," said Patrick O'Hare at Briefing.com.
"There was a glowing report from the headliner -- ie, Apple -- and there has been a litany of better-than-expected results cutting across economic sectors."
Apple reported forecast-smashing results. The gadget maker said after Wednesday's market close that it nearly doubled its quarterly net profit on record iPhone sales and revenue soared 83 per cent.
Apple chief executive Steve Jobs said the company was "firing on all cylinders." Investors appeared to agree: Apple shares bounced 2.9 per cent higher to $352.41.
US conglomerate General Electric on Thursday posted a nearly 80 per cent jump in net profit in the first quarter compared with the same period a year ago, sharply topping market expectations.
But shares in GE, considered a bellwether of the US economy because of its sprawling businesses, fell 1.8 per cent to $20.04.
The action came as investors face a three-day Easter holiday weekend. The financial markets will be closed Friday.
"Typically, the stock market rallies ahead of a long weekend as traders often move to cover some short positions," Frederic Dickson at DA Davidson & Co.
On Wednesday, the Dow closed up 1.52 per cent at 12,453.54, the highest closing level for the blue-chip index since June 5, 2008, as investors cheered robust earnings reports. The Nasdaq leaped 2.10 per cent and the S&P 500 was up 1.35 per cent.
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