The artificial-intelligence trade was chugging along as investors waited for Wednesday's consumer-price inflation data, which could help decide if the Federal Reserve has scope to continue holding interest rates at current levels.

Super Micro Computer Inc. stock added 3% ahead of the opening bell on Monday. The AI server maker is set to report its fourth-quarter earnings on Thursday.

Lumentum rose 3.7%, Coherent gained 2.4%, Applied Materials climbed 2.4%, and Corning advanced 1.8% in premarket trading. Dell, Intel, and Marvell were among the other AI stocks rising.

Apple dropped 1% after The Wall Street Journal reported that the iPhone maker was testing memory chips from China's ChangXin Memory Technologies, citing people familiar with the matter. Apple didn't immediately respond to a request for comment from Barron's.

Berkshire Hathaway ticked up 0.4% after the conglomerate reported solid, but not great second-quarter earnings on Saturday. Berkshire's after-tax operating earnings rose 16% from a year ago to $13 billion, but a swing in one-time currency gains and losses drove most of the gains.

Sunrise Energy Metals closed 16% higher after the Trump administration awarded a $400 million loan to the Australian company, which is attempting to mine scandium, a rare chemical element used to strengthen aluminum.