South Korea's KOSPI index fell 19.3% in the third quarter, marking its steepest quarterly decline since the first quarter of 2020. The benchmark closed at 6,838.04 on September 30, down 32.77 points or 0.48% on the day. The significant quarterly contraction highlights mounting pressure on South Korean equities as the market posted its worst performance in over six years. This downturn represents a major shift in sentiment for one of Asia's key financial indices.