Marvell, Sandisk, SK Hynix lead semiconductor stock rally as S&P 500 trades at record highs

Semiconductor stocks rallied Tuesday, with the PHLX Semiconductor Index surging over 6% and the S&P 500 reaching record highs, as Marvell Technology launched new AI-optimized memory products at the Flash Memory Summit 2026 and investors awaited AMD's quarterly results. Marvell shares jumped 14%, Micron rose 8%, SK Hynix gained 6%, AMD climbed 7%, and Intel advanced 10%, while Nvidia added nearly 2%.

What happened: Semiconductor stocks rallied on Tuesday, with the PHLX Semiconductor Index SOXX https://finance.yahoo.com/quote/SOXX/ surging over 6%, helping send the S&P 500 ^GSPC https://finance.yahoo.com/quote/%5EGSPC/ to new highs. US-listed shares of memory and storage leaders Micron Technology MU https://finance.yahoo.com/quote/MU/ and SK Hynix SKHY https://finance.yahoo.com/quote/SKHY/ jumped 8% and 6%, respectively. Shares of Marvell Technology MRVL https://finance.yahoo.com/quote/MRVL also rallied 14%. AI chip heavyweight Nvidia NVDA https://finance.yahoo.com/quote/NVDA/ gained nearly 2%, while shares of AMD AMD https://finance.yahoo.com/quote/AMD/ jumped 7% ahead of the company's quarterly results. Chipmaker Intel INTC https://finance.yahoo.com/quote/INTC rose 10%. What's behind the move: Marvell Technology launched the Flash Memory Summit 2026 in California on Tuesday, introducing new AI-optimized memory and storage infrastructure products to meet growing compute demands of agentic AI inference. Investors also awaited results from AMD, which reports after the close on Tuesday. Market watchers were expecting explosive moves either to the upside or the downside. "AMD — this is a company that tends to be so good at guiding the Street," Cboe senior vice president JJ Kinahan told Yahoo Finance on Monday. "They have been within a penny for the last 12 earnings reports in terms of where they are going to be. However, on more than half of them, they actually sold off afterward," he noted. What else you need to know: The semiconductor index led market gains on Tuesday as the S&P 500 and the Dow Jones Industrial Average DJI https://finance.yahoo.com/quote/%5EDJI/ both headed toward record closes. https://finance.yahoo.com/markets/live/stock-market-today-tuesday-august-4-dow-sp-500-nasdaq-100140227.html The rally follows a volatile stretch for AI infrastructure stocks, driven by concerns about overinvestment and intensifying competition from China. Semiconductor stocks have been at the center of the AI trade this year but tumbled from record highs into bear-market territory last month, dropping more than 20% from their highs as investors grow increasingly concerned about hyperscalers' massive AI spending spree. Worries about China's advancement in AI, driven by less expensive models, have also weighed on the AI infrastructure trade. Ines Ferre is a senior business reporter for Yahoo Finance. Follow her on X at @ines ferre . Click here for in-depth analysis of the latest stock market news and events moving stock prices Read the latest financial and business news from Yahoo Finance