Marvell Technology surged 10% Monday and added 4% premarket after S&P Dow Jones Indices announced its inclusion in the S&P 500 later this month, a move that automatically triggers index-tracking fund buying. Other chipmakers including Intel, Nvidia, and Qualcomm joined the recovery as tech stocks rebounded from Friday's selloff, with the sector benefiting from AI-driven demand. The moves come as SK Hynix shares jumped 16% and Samsung Electronics rose 9% in Seoul trading, extending gains from the previous day's AI-fueled rally.

Vail Resorts slipped in early trading after cutting its annual forecast, citing continued pressure from low snowfall that's depressed visits and revenue. Meanwhile, GSK shares retreated following the U.K. pharmaceutical company's agreement to acquire Boston-based cancer-drug developer Nuvalent for $10.6 billion, a deal that underscores the sector's aggressive pursuit of oncology assets amid improving pipeline prospects.

Perrigo dropped over 2% premarket after both its CEO and president resigned, citing violations of company conduct policies by the departing CEO. The leadership changes come amid ongoing scrutiny of governance issues at the over-the-counter drug manufacturer. Separately, the Pentagon named Chinese tech giants Alibaba and Baidu among two dozen companies barred from U.S. military business for allegedly supporting Beijing's military expansion.

The mixed session reflects investors navigating between AI-driven growth themes and traditional economic pressures, with chip stocks leading gains while travel and pharmaceutical sectors face company-specific headwinds.