Korean stocks’ rebound failed and then crashed again, down 7.5%. SK Hynix plunged nearly 13%, while Samsung Electronics fell again by 8%.

KOSPI index on the 29th flipped from red to green to red, triggering a sell Sidecar twice intraday. The drop exceeded 7%. SK Hynix plunged nearly 13%, while Samsung Electronics tumbled 8%.
（Background: Korean stocks again hit a circuit breaker; the Nikkei plunged 4%; Taiwan stocks dropped 1,800 points and fell below 42k—value-stock panic selloff）
（Background addition: JPMorgan Chase: KOSPI plunged 28%, and leverage liquidation looks bullish）

This (29) day at the open, the Korean Composite Stock Price Index KOSPI rose once by 1% to 2%. The market initially expected a rebound after the selloff. Samsung Electronics even turned green briefly, up 2.50%; but the rebound couldn’t last for even an hour. In the early part of 10 o’clock, another sell Sidecar (a temporary trading halt mechanism) was triggered again. Optimism was instantly crushed; by the time the report was due, the decline had widened to 7.5%.

The downtrend in Korean stocks was mainly driven by pressure from semiconductor heavyweight shares. SK Hynix shares fell sharply 12.89%, and Samsung Electronics also dropped nearly 8%, amplifying the index’s overall decline.

The disastrous circuit-breaker case from yesterday is still fresh in memory

In the previous trading day, KOSPI opened at 6,400.27 points and closed at 6,023.63 points. It plunged 732.12 points, a decline of 10.84%, marking the 8th circuit breaker triggered this year. Samsung Electronics sank 13.58%, posting the largest single-day drop in nearly 20 years; SK Hynix also fell 14.48%.

So far in July, KOSPI has cumulatively plunged 34%. Korea ETF assets have also evaporated rapidly. From more than 500 trillion won on July 1, they shrank to 418 trillion won on July 28. In less than a month, more than 80 trillion won has been wiped out.

Memory supply dominance loosens, and AI peak concerns spread simultaneously

It’s hard to say this correction means the fundamentals have already broken, but retail panic sentiment is indeed swinging violently.

The first spark is the loosening of China’s memory layout. On the first day of listing, CXMT (ChangXin Memory) surged 465%. Combined with reports that China’s indigenous DUV lithography equipment has made a breakthrough, the market is questioning how long the oligopoly in memory—Samsung Electronics, SK Hynix, and Micron—can hold.

The second spark is renewed “AI capex peak” concerns. Alphabet’s free cash flow turned negative for the first time since it was listed in 2004, with a gap of $5.9 billion. The market is questioning whether cloud providers pouring huge sums into building AI data centers can generate returns—concerns spread quickly to US stocks’ semiconductors: the Philadelphia Semiconductor Index fell 4.49%, marking four consecutive red days; Micron dropped 8.85%, AMD fell 8.15%, Intel slid 5.86%, and Nvidia fell 4.99%.

The third spark is that even strong earnings don’t stop valuation correction. SK Hynix’s operating profit in the second quarter rose 557% year over year, but it still fell short of the market’s expected 64.68 trillion won, showing that bullish sentiment had been priced in early.