Artificial intelligence is still key to U.S. equity gains, according to Capital Economics' Thomas Mathews in commentary. The past few weeks have seen concerns raised about the health of the AI rally, says the head of markets, Asia Pacific. "We don't think the AI rally has run out of steam," he says. One reason not to panic is that tech earnings, which have driven the rally so far, are "showing little sign of wobbling," he says. In fact, the tech sector's earnings estimates have risen at "an almost unprecedented rate," he says. Investors will be closely watching the coming U.S. earnings season, as well as Samsumg's earnings in South Korea this week, CE says. (tracy.qu@wsj.com)