Shares of South Korean memory chip giant SK Hynix fell by as much as 5.2% in Seoul trading today, 18 July 2026, reigniting concerns among global investors about the sustainability of the artificial intelligence boom. The decline marks one of the steepest single-day drops for the company in recent months, with the stock closing the morning session at 182,500 won.
The sell-off was triggered by reports suggesting that major cloud computing customers may be scaling back orders for high-bandwidth memory (HBM) chips, a key component in AI training hardware. Analysts pointed to growing fears of an oversupply in the memory market, as rival manufacturers ramp up production. 'The market is now pricing in a potential correction after months of exuberance,' said one Seoul-based semiconductor analyst.
The move rippled through Asian tech indices, with the KOSPI index slipping 1.1% and the broader semiconductor sector under pressure. For UK investors, the impact is felt indirectly through exchange-traded funds (ETFs) and pension portfolios that hold significant positions in Asian technology stocks. The FTSE 100 remained largely flat at 8,320 points, but technology-heavy investment trusts saw modest declines.
SK Hynix had been a standout performer in 2025, benefiting from surging demand for AI infrastructure. However, today's slide highlights the sector's vulnerability to shifting sentiment. 'We are seeing a rotation out of high-growth tech into more defensive sectors,' commented a London-based fund manager. 'UK investors with exposure to global tech should brace for continued volatility.'
The broader context includes ongoing trade tensions between the US and China, which have added uncertainty to semiconductor supply chains. While SK Hynix's long-term outlook remains tied to AI adoption, short-term headwinds from inventory adjustments are weighing on sentiment. No official guidance has been issued by the company today.