SEOUL, July 9 : Demand for SK Hynix's $28 billion U.S. share sale was more than seven times available shares, a person familiar with the matter said, underscoring huge investor appetite for a pivotal company in the AI supply chain.The offering from the South Korean chipmaker, which will finance new factories and equipment to meet surging AI chip demand, is set to be the world's second-biggest share sale after SpaceX's record-breaking $85.7 billion IPO last month.SK Hynix declined to comment. The person declined to be identified as details of the share sale were confidential.In addition to bringing in funds, SK Hynix's U.S. listing is expected to help it narrow its valuation gap with U.S. rival Micron, which, despite having less market share in key memory products, has benefited from direct access to the world's largest pool of investors.

Micron currently trades at a 12-month forward price-to-earnings ratio of 6.66 times versus SK Hynix's 5.5 times.HUGE SHARE GAINS REFLECTING SURGING EARNINGSSK Hynix has made its fortune by becoming the most sought-after supplier of high-bandwidth memory (HBM) chips, a culmination of 14 years of bets that brought it skepticism and scorn but ultimately put it at the centre of the global AI gold rush."As long as there is demand for graphic processors and AI data centers, SK Hynix is indispensable," said Yoo Hoi-jun, an electrical engineering professor at the Korea Advanced Institute of Science & Technology.Nvidia CEO Jensen Huang said last month that SK Hynix would continue to be the U.S. AI chipmaker's largest partner, adding that the current memory chip shortage would persist for a few years due to strong demand.Though shares in semiconductor companies globally have lost momentum in recent weeks, firms like SK Hynix and rival Samsung Electronics are sitting on historic gains as insatiable demand for computer chips to power AI data centres has sent profits soaring.SK Hynix shares closed up 5 per cent on Thursday but have dropped by a quarter in the last two weeks. Even so, the stock is up 680 per cent for the past 12 months. As dizzying as that longer-term share jump has been, the shares have not outpaced massive gains in profits — earnings so huge that each employee is expected to get an annual bonus of about $574,500, making them highly sought-after marriage partners.Tellingly, the firm's 12-month forward price-to-earnings ratio has dropped, with its current level of 5.5 times down from 7.9 times at end-October.TRADE BEGINS ON FRIDAYSK Hynix plans to set the ⁠final price of the ADR offering on Thursday and the ADRs will start trading on the Nasdaq ​on July 10.Ten ADRs will represent ⁠one common ​share and a Monday filing gave a reference ​price of 242,500 won per ADR, based on SK Hynix's July 3 closing price in Seoul. On Thursday, the stock closed at 2,186,000 won.SK Hynix has said that Baillie Gifford Overseas, investment funds managed by Coatue Management and Situational Awareness Partners have each ​indicated interest in purchasing up to a combined $7 billion of its U.S. ADRs.Lee Min-hee, an analyst at BNK Investment & Securities, said that contrary to some market expectations, he did not expect SK Hynix's U.S. listing to result in a major boost to its local shares.Domestic companies still need to contend with the so-called Korea discount — the tendency for them to trade at lower valuations due to concerns about corporate governance, he noted.