South Korean shares posted a record rebound on Friday after three sessions of heavy selling. The benchmark KOSPI closed 17.9% higher at 6,695.45, marking its largest daily gain. The move recovered much of the index’s earlier 17% decline. However, it stayed below its June peak above 9,000. The close also surpassed the previous rebound record set during the 2008 financial crisis.
Chipmakers drove most of the recovery. SK Hynix gained 30%, while Samsung Electronics rose 28%. Buyers returned after strong Microsoft and Amazon earnings eased concerns about spending on artificial intelligence infrastructure.
SK Hynix and Samsung Electronics carry large weightings in the KOSPI. Their sharp gains lifted the wider market as investors bought shares hit hardest during the earlier rout. SK Hynix supplies high-bandwidth memory chips used in Nvidia’s advanced AI computing systems.
Both companies had fallen heavily during the three-day decline. Investors questioned whether large technology companies could earn enough from their AI spending. Concerns about stronger Chinese competition also added pressure across semiconductor shares. Friday’s rally reversed part of those losses but did not restore the KOSPI to its June record.
The KOSPI’s previous largest daily gain was almost 12% in October 2008. Recent swings have occurred more often as chip stocks gained a larger share of the index. Samsung and SK Hynix represented about 52% of KOSPI market value by mid-July, according to South Korea’s financial regulator.
Meanwhile, the change in sentiment followed strong results from major US technology companies. Microsoft reported better-than-expected quarterly earnings and forecast cash generation through fiscal 2027. Amazon then posted its strongest cloud growth in more than four years. The figures supported demand for companies tied to data centers and AI computing.
Microsoft shares jumped 15.5% on Thursday, while Amazon gained about 9% in after-hours trading. The results supported chip stocks across Asia. Japan’s Nikkei 225 gained 4%, and Taiwan’s Taiex climbed 8%. TSMC rose 10% as investors returned to semiconductor companies after the regional sell-off.
However, South Korean officials have introduced new controls after large daily swings became more common. Retail investors have used single-stock leveraged exchange-traded funds linked to Samsung and SK Hynix. These products multiply daily gains and losses, increasing market moves when traders enter or leave similar positions together.
The Financial Services Commission suspended new listings and advertising for single-stock leveraged products on July 16. From July 31, investors must hold 30 million won in cash before trading them, up from 10 million won. The regulator said the earlier start aimed “to quickly help to stabilize demand.”
Additionally, authorities plan to limit individual exposure to single-stock leveraged ETFs to 20% of total investment assets. They will raise costs for heavy trading and require added investor training. The rules followed repeated circuit-breaker events and sharp KOSPI movements during 2026.
More than half of all KOSPI circuit breakers in the market’s history occurred during the past six months. The mechanism pauses trading after set market moves. Friday’s record rise came after several controls took effect, adding another large movement to an already volatile year.