South Korea's benchmark KOSPI index closed down 2.04%, or 173.07 points, to 8,303.41 on Wednesday, driven by sustained selling from overseas investors.
The decline marks a significant session loss, reflecting ongoing risk aversion among foreign capital managers operating in the region.
7 trillion won ($3.3 billion) of South Korean equities in May.
The sell-off underscores a deepening liquidity challenge for the market.
According to data released earlier in the week, foreign investors offloaded a record net 4.7 trillion won ($3.3 billion) of South Korean equities in May.
This unprecedented monthly outflow represents the largest sell-off in the market's history, signaling a structural shift in foreign sentiment toward Korean assets.
The persistent pressure from overseas funds has weighed heavily on major blue-chip names, including Samsung Electronics (005930.KS) and Hana Financial Group (000350.KS), as traders digest the scale of the capital flight.