Marvell, SanDisk, and SK Hynix lead a semiconductor stock rally as the S&P 500 trades at record highs on AI momentum.

Semiconductor stocks rallied sharply on Tuesday, with the PHLX Semiconductor Index (SOXX) surging over 6% and helping propel the S&P 500 to new record highs. The gains were broad-based across the sector, with Micron Technology (MU) jumping 8%, SK Hynix (SKHY) rising 6%, Marvell Technology (MRVL) rallying 14%, and Advanced Micro Devices (AMD) gaining 7%. Intel (INTC) climbed 10%, SanDisk (SNDK) rose 10.84%, Broadcom (AVGO) advanced 6.61%, and Nvidia (NVDA), the AI chip heavyweight, gained nearly 2%.

The momentum was driven in part by Marvell Technology's launch of the Flash Memory Summit 2026 in California on Tuesday, where the company unveiled new AI-optimized memory and storage infrastructure products designed to address the growing compute demands of agentic AI inference. Investors were also focused on AMD's quarterly earnings announcement, expected after market close on Tuesday. According to Cboe senior vice president JJ Kinahan, AMD has demonstrated exceptional accuracy in guiding the Street, hitting expectations within a penny for the last 12 earnings reports. However, he noted that the stock has sold off after results in more than half of those cases, signaling that investors should expect potentially explosive moves either way.

The semiconductor sector's leadership on Tuesday marked a significant rebound after a volatile period for AI infrastructure stocks. The sector had tumbled from record highs into bear-market territory last month, declining more than 20% as investors grew concerned about hyperscalers' massive spending on AI and the mounting competition from China's increasingly capable, lower-cost AI models. Tuesday's rally reflected renewed optimism in the semiconductor complex and broader market momentum, as both the Dow Jones Industrial Average (DJI) and S&P 500 approached record closes.