The KOSPI index briefly surpassed 8,000 points intra-day before falling more than six% by the market close on May 6, 2024 [1], [2].
This volatility highlights the fragile nature of the current rally and the impact of automated trading quotas on South Korean market stability.
The surge to 8,000 points occurred just seven trading days — and nine calendar days — after the KOSPI first passed the 7,000-point mark [1]. Despite the historic milestone, the market faced a sharp reversal as foreign and institutional investors sold approximately 7 trillion won [1]. Individual investors bought a similar amount to absorb the sell-off [1].
Market analysts attribute the crash to mechanical selling. As the index rose, foreign and institutional holdings exceeded preset quota limits, forcing these investors to reduce their positions regardless of market sentiment [1].
Yeom Seung-hwan, a director at LS Securities, said that because there are fixed proportions for foreigners, when the price or index rises, they exceed those proportions. He said that regardless of whether it is good or bad, they must sell mechanically to reduce their weight [1].
Concurrent with the stock market volatility, the foreign-exchange market saw the KRW/USD rate rise to approximately 1,500 won per dollar [1]. This currency fluctuation added pressure to the trading environment as the index retreated from its peak [1].
The rapid ascent to the "8,000 era" and the subsequent plunge within a single session underscore the influence of institutional rebalancing over fundamental growth [1], [2].
“KOSPI briefly surpassed 8,000 points intra-day before falling more than 6% by the market close”
The event demonstrates how 'mechanical selling' can trigger a flash crash even during a bull market. When institutional investors operate under strict portfolio weight constraints, a rapid price increase paradoxically forces them to sell to maintain those ratios. This creates a ceiling for the KOSPI, where technical quota limits may override positive economic sentiment, while the simultaneous rise of the KRW/USD rate suggests a broader flight from the won.
