Why is SK Hynix stock plunging today?

SK Hynix Inc.'s stock experienced an 8.2% decline, hitting ₩1,473,000 on Tuesday, as a combination of Chinese competition, global selling, and a weakening semiconductor sentiment contributed to the stock's fifth day of losses. The main catalyst behind this downturn was China's ChangXin Memory Technologies (CXMT), which announced plans to launch DDR5 RDIMM server memory products using a next-generation 4F² chip architecture by the end of 2026.

This new design features memory cells in a denser configuration compared to traditional layouts and poses a direct threat to SK Hynix's high-margin server memory segment, which it has historically dominated.

Furthermore, SK Hynix faced persistent foreign and retail selling in South Korean markets. According to early KOSPI data, foreign traders sold ₩5.35 billion worth of local stocks on Tuesday, while retail selling amounted to ₩3.72 billion. The overall market environment added to the market damage, as South Korea's KOSPI fell more than 5% intraday, briefly dipping below the 6,000 level and triggering a sell-sidecar circuit breaker for the sixth consecutive session.

Simultaneously, the Philadelphia Semiconductor Index experienced a 2.67% decline, negatively impacting U.S. memory peer Micron, and this weakness also permeated Seoul's market opening.

Additionally, the uncertainty surrounding Q3 earnings from industry leaders ASML and TSMC, scheduled to be released this week, further pressured chip stocks. Consequently, this article, generated with the assistance of artificial intelligence, was reviewed by an editor for accuracy.