South Korea's main stock exchange launched its first after-hours session on Monday, introducing around-the-clock trading to attract global investors. The extended session saw erratic and retail-dominated trading, with volatility spikes triggering 1,637 trading halts in individual stocks. Institutional traders largely stayed on the sidelines, leaving retail investors to account for 93% of the 1.8 trillion won ($1.34 billion) total turnover. Foreign investors accounted for just 3.9%, while local institutions made up the remainder. The Korea Exchange now offers late trading between 4 p.m. and 8 p.m. Seasoned investors warned that smaller stocks experienced extreme swings, jumping 15% to 30% on minor news before dropping quickly. The launch represents the first step by a major Asian exchange toward 24-hour trading, joining other markets like Nasdaq Inc. and the New York Stock Exchange exploring similar moves to tap international demand.

Extended hours are seen as a way to level the playing field for retail traders and allow quick action on late-breaking news. However, without bigger players providing more liquidity, the session is likely to remain risky. The volatility interruption mechanism was activated multiple times across 2,501 different stocks traded in the evening hours. Market participants are bracing for continued volatility as global exchanges look to keep pace with 24-hour electronic platforms.