About 15 minutes into trading, the tech-rich Nasdaq Composite Index was up 0.7 percent at 7,166.41.
The Dow Jones Industrial Average rose 0.1 percent to 24,333.76, while the broad-based S&P 500 advanced 0.3 percent to 2,674.36.
Analysts were cheered by a torrent of strong technology sector earnings led by Amazon, which surged 6.2 percent after reporting that its quarterly profit had more than doubled to $1.6 billion.
Microsoft jumped 2.2 percent after its report and Intel rose 2.8 percent. The strong results followed blowout earnings from Facebook on Wednesday that mollified worries about technology share valuations.
US growth came in at 2.3 percent in the January-March period, according to government data, down from 2.9 percent in the final quarter of 2017 but better than analyst expectations.
However, some commentators expressed disappointment at sluggish consumer spending, which rose just 1.1 percent during the quarter.
Petroleum producers were mixed, with ExxonMobil slumping 3.9 percent after profits missed analyst expectations and Chevron advancing 0.6 percent after earnings topped expectations but revenues fell short.