Demand for SK Hynix's proposed $28 billion share sale in the United States exceeded the number of shares on offer by more than seven times, according to a report by Reuters. The strong response highlights robust investor appetite for one of the key companies powering the global artificial intelligence (AI) supply chain.The South Korean memory chipmaker is raising funds to finance new factories and equipment as it ramps up production to meet soaring demand for AI chips. The offering is expected to become the world's second-largest share sale, following SpaceX's record-breaking $85.7 billion initial public offering last month.SK Hynix declined to comment on the demand for the offering. The person cited by Reuters also declined to be identified because the details of the transaction remain confidential.Investor optimism lifted SK Hynix shares by about 6% in morning trading on Thursday.According to Reuters, underwriters have informed investors that pricing guidance is expected after the South Korean market closes on Thursday, with share allocations to be finalised later in the U.S. trading day.Although semiconductor stocks have lost some momentum globally in recent weeks, AI-related chipmakers such as SK Hynix and Samsung Electronics continue to trade near historic highs after a prolonged rally driven by booming demand for chips used in AI data centres.SK Hynix shares have fallen roughly 25% over the past two weeks following their sharp run-up. Despite the recent correction, the stock remains up around 680% over the past 12 months.The company has emerged as the leading supplier of high-bandwidth memory (HBM) chips for Nvidia, cementing its position at the heart of the AI hardware ecosystem after years of investment in the technology.Bloomberg had earlier reported that the share sale was oversubscribed by more than seven times.