KOSPI · September 7, 2026
An AI model launch, then a chip rally
+4.61%
single-day change vs previous close
What happened that day?
- Monday, 7 September 2026 — the KOSPI rose 4.61% to close at 6,995.39, a few points short of 7,000
- The trigger came from the US. OpenAI unveiled a new model the previous Thursday, and American chip stocks jumped on the Friday
- Korea took all of it in one session on Monday. The announcement day and the day the price moved were not the same day
- The new model was described as running on far more compute — which reads as more demand for memory chips
- Samsung Electronics and SK Hynix both surged. The two carry so much index weight that their day becomes the index's day
- Foreign and institutional investors bought heavily on the same side; retail investors sold into it
- This market had fallen 38.63% from late June to the end of July. The big daily swings are part of climbing back out
Sources
Every figure on this page is recomputed from the original daily closing prices and checked against them at build time. The account of what happened is put together from the public record; where a specific source was consulted it is listed above.