The Nasdaq Composite ended at a record high on Thursday, boosted by results-related gains in Comcast, PayPal and Intuit.
Amazon and Alphabet jumped more than 4% each after the bell, following stellar earnings.
The S&P 500 and the Dow were little changed.
Comcast rose 2.1% to $39.59 after touching a record high of $40.62 as strong subscriber growth brought a forecast-beating profit.
Much of the stock movement came in response to the quarterly earnings that a slew of companies are sharing with investors this week.
American Airlines shares plummeted 5.2% after its release on Thursday, which included a 2% revenue increase - and the news it would provide raises to pilots and flight attendants.
Rival carriers also came under pressure, with Delta down 1.4% and United Continental down about 1%.
United is trying to move past bad publicity over its removal of a passenger from a flight, a case the company said it settled on Thursday.
Under Armour shares soared 9.3%, despite the sportswear maker reporting its first quarterly net loss since the company listed on the market in 2005.
It reported a net loss of $2.3m for the three months to March after a sharp fall in profit at its North American operations. However, the shares jumped as the loss was not as bad as feared.