KOSPI Sinks 23% in July 2026 as South Korea Sees Record Circuit-Breaker Halts

South Korea's equity market posted its steepest monthly decline on record in July 2026. The benchmark KOSPI slid about 23% over the month, erasing roughly ₩250 trillion in market value and setting a new high for circuit-breaker trading halts. The selloff followed a sharp reversal from June's exuberance, when AI and semiconductor optimism lifted major technology names to historic valuations. The KOSPI hit a peak of 9,114 in June 2026, then fell below 8,000 by early July. On July 7, accelerating losses triggered the sixth circuit breaker of 2026, an automatic halt designed to curb disorderly selling when declines breach preset thresholds. Pressure intensified on July 13. The index closed at 6,806.93, down 8.95% in a single session, setting off the seventh circuit breaker of the year. By mid-month, the KOSPI was trading between 6,500 and 7,200, more than 20% below its June high. Some reports put the peak-to-trough decline at over 31%. Selling was most severe in Samsung Electronics and SK Hynix, the two heavyweight constituents that dominate the KOSPI's market capitalization. During the worst sessions, both stocks repeatedly logged one-day drops in the 9% to 12% range. Market participants pointed to a rapid reassessment of the durability of AI chip demand as the immediate catalyst. After months of pricing in near-unlimited semiconductor appetite tied to the global AI buildout, any sign of cooling expectations triggered a violent unwind. Foreign investors and institutions maintained steady selling throughout the month, while the growing use of leveraged ETFs among Korean retail traders amplified the decline. As leveraged products rebalance into a falling market, they can mechanically increase selling, reinforcing a downward feedback loop. By mid-July, seven circuit-breaker activations had already surpassed the annual totals seen in most prior calendar years. The move also carried global implications. South Korea is widely viewed as a bellwether for technology demand given its central role in semiconductor production. Samsung and SK Hynix account for a large share of global memory-chip supply, so sharp drawdowns in their shares are watched well beyond Seoul. For investors and regulators, the episode sharpened scrutiny of leveraged ETF risks. Authorities worldwide have increasingly monitored the rapid growth of leveraged and inverse products, and a sequence of seven circuit-breaker halts in half a month is the kind of market stress that can accelerate regulatory responses.