KOSPI · August 20, 2026

Two buyback plans in one morning

+5.89%

single-day change vs previous close

What happened that day?

The KOSPI rose 5.89% to close at 6,852.58, recovering most of the previous day's loss
The trigger was a pair of large shareholder-return plans announced by Samsung Electronics and SK Hynix
Buying back and cancelling shares leaves fewer of them to split the same profit. Each remaining share is worth more, so the price rises
Falling government bond yields — the thing that had pressed the market the day before — worked the other way. The direction flipped in a single session
A buy-side sidecar was triggered during the session
Bank of Korea figures around this time showed foreign holdings of Korean financial assets at a record quarterly high
This market had fallen 38.63% from late June to the end of July and was still climbing back. The size of the daily swings was the aftershock of that

Sources

KOSPI

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.