Shares of a broad set of chipmakers rallied late on Wednesday, collectively adding about $400 billion in market capitalization after forward-looking comments from Micron Technology and Qualcomm shifted sentiment back toward AI-related hardware plays.
Micron led the move among memory makers, rising 12% in after-hours trading after it forecast quarterly earnings that surpass analysts' estimates. The company said demand for its memory chips will be driven by heavy investments in AI-related infrastructure, a view investors rewarded with a strong late-session response.
Also after the close, Qualcomm said it expects its data center business to generate $15 billion in sales by 2029, signaling a strategic push beyond its traditional smartphone chip business toward AI-focused data-center processors. That projection helped lift chip-equipment and design peers across the market.
Competitors and related suppliers saw notable gains: Western Digital, Sandisk and Seagate Technology - direct rivals to Micron in memory and storage - each jumped more than 8%. Chip and IP-related names also rose, with Arm Holdings up about 6%, Marvell adding almost 4% and Broadcom climbing 2%. Manufacturers of specialized semiconductor production tools were higher as well, with Applied Materials and ASML both rising more than 4%.
The upbeat guidance arrived after a recent pullback in chip stocks that had raised concerns about valuation levels for AI-linked companies. The PHLX chip index had fallen 8% on Tuesday amid investor worries that the massive capital spending required to build AI data centers may not translate promptly into higher revenue and profit. Despite this week's volatility, the PHLX chip index remains up 90% so far in 2026.
Micron's performance this year has been particularly dramatic: excluding the late-day rally on Wednesday, the company has gained more than 260% year to date. The sharp moves underline the market's sensitivity to forward-looking revenue signals from companies tied to AI infrastructure and memory demand.
While the late-session forecasts from Micron and Qualcomm restored momentum to chip stocks, the episode underscores lingering questions among investors about timing and valuation as the industry scales the infrastructure needed for large AI deployments.