On Tuesday, shares of semiconductor companies such as Micron, Micron Technology, and SK Hynix fell, extending the previous trading day’s decline. The PHLX Semiconductor Index had already dropped more than 2%.The sell-off was driven by declines in overseas semiconductor stocks, with South Korea’s SK Hynix falling more than 14% and Samsung Electronics dropping more than 13%. Investor concerns about the return on massive spending by hyperscale companies in artificial intelligence (AI) and increasingly fierce competition from Chinese chipmakers have heightened market uncertainty.