Shares of technology companies rose as the momentum in the sector continued to lure speculators.

The prices of Apple, Amazon.com, Microsoft and other mega-cap tech stocks have risen by 50% or more since March, as momentum traders continue piling into bets that the digital economy will thrive, no matter what course the pandemic takes from here.

"The dominance of growth stocks is one of the biggest stories for the market in 2020," said Jeffrey Buchbinder, an equity strategist with brokerage LPL Financial, in a note to clients.

"Stronger balance sheets, better earnings, and favorable positioning for the work-from-home trend suggest this historic run for growth stocks over the past decade may still have legs."

Apple rose Wednesday despite warnings from brokerage Deutsche Bank that the iPhone maker's shares may have "overreacted" to recent positive data points.

Shares of Tesla gave back a modicum of their recent gains but remained above $1360, more than triple the price they started the year.

The Nasdaq Composite has seen the strongest opening to the second half of a calendar year since 2003, according to the Wall Street Journal Data Group.

High-end graphics chipmaker Nvidia passed personal-computer chip giant Intel in market value for the first time Wednesday. 



  Write to Rob Curran at rob.curran@dowjones.com