The KOSPI closed at 6,598.87 (-1.38%) as profit-taking emerged following a recent rally that saw the index approach its 52-week high. The day's range spanned from 6,597.83 to 6,750.27, reflecting heightened volatility as investors reassess their positions amid concerns over potential overvaluation.

From a technical perspective, the KOSPI remains above both its 20-day and 50-day simple moving averages (SMA), currently at 6,132.01 and 5,825.99, respectively, indicating a bullish trend in the medium term. However, with the 14-day Relative Strength Index (RSI) at 83.8, the index is considered to be in overbought territory, suggesting a potential correction could be on the horizon.

Looking ahead, key support levels to monitor are the 20-day SMA at 6,132.01 and the psychological barrier of 6,500. A decisive break below these levels could trigger further selling pressure, while a rebound could reignite bullish momentum towards the all-time high of 6,690.90.