Samsung Electronics said a report claiming its high-bandwidth memory 4 (HBM4) chips had cleared Nvidia’s reliability tests is “groundless,” according to comments relayed by Jefferies’ trading desk on Wednesday. Earlier in the day, Jefferies had circulated a note calling the purported test clearance a “sensational headline,” adding that Samsung was poised to begin pre-production in late August and move to mass production in November or December—well ahead of the market’s expectation for 2026. The rumor triggered selling in competing memory suppliers, with Jefferies warning of downside risk for Micron Technology and potential rotation away from SK Hynix. Samsung’s swift denial removes immediate questions about the competitive timeline for next-generation HBM4 supply to Nvidia, which is seeking additional sources beyond SK Hynix for the memory used in artificial-intelligence accelerators. Market attention now shifts back to the formal qualification schedules the chipmaker discloses in its earnings calls and regulatory filings.