SK Hynix IncAI chip rally drives demand for SK Hynix's memory chips, boosting its stock and weighting.
South Korea's Kospi Index has seen return volatility exceed 60% as of July 20, nearly double that of Japan's Nikkei 225 and higher than Bitcoin's volatility over the same period, driven by an AI-fueled rally in semiconductor stocks. The Korea Exchange activated its circuit-breaker mechanism seven times through mid-July, compared with no suspensions in 2025 and only one in 2024. Samsung Electronics and SK Hynix, both suppliers of memory chips for artificial intelligence, now account for more than 50% of the Kospi's weighting, meaning funds tracking the broader market are heavily exposed to just two companies and the global AI investment cycle. Retail investors have poured more than 100 trillion won, or approximately $67 billion, into Kospi shares this year, while foreign investors sold about $108 billion, including more than $40 billion from SK Hynix, as fund managers trimmed positions to avoid excessive concentration. Leveraged exchange-traded funds linked to Samsung and SK Hynix have amplified swings, with assets in Korean leveraged ETFs climbing above $40 billion from $5 billion at the start of the year, prompting regulators to temporarily suspend new listings of single-stock leveraged products on July 16.
SK Hynix IncAI chip rally drives demand for SK Hynix's memory chips, boosting its stock and weighting.
Samsung Electronics Co LtdAI chip rally drives demand for Samsung's memory chips, boosting its stock and weighting.