돈經濟

Immediately after the market closed on October 13, 2026, the Korean stock market plummeted so sharply that the term 'Black Tuesday' would not be an exaggeration. The KOSPI closed at 6035.35, down 5.46% from the previous day, and even fell to the 5,911 level during trading, threatening the 6,000 mark. Foreign investors net sold approximately 4.5 trillion won in KOSPI on this day alone, and the cumulative net selling volume this year is close to 200 trillion won. Although individuals and institutions net bought around 2 trillion won and 1 trillion won respectively, absorbing the selling volume, it was not enough to stem the foreign selling spree.

At the center of the index decline were Samsung Electronics and SK Hynix. Samsung Electronics closed down 7.39% at 232,000 won, and SK Hynix plummeted 10.09% to 1,443,000 won. The market revealed a severe discrepancy between performance and stock price, especially given that Samsung Electronics had announced just a few days earlier a preliminary third-quarter operating profit of 107.4 trillion won, a 782% increase from the same period last year. With the index already having corrected by more than 30% from its June high (around 9,385 during trading, 9,114 based on closing price), foreign investor supply and demand once again led the downward pressure.

Several factors are simultaneously contributing to the large-scale withdrawal of foreign capital. The most direct catalyst is skepticism about the sustainability of AI investment. With OpenAI's annualized revenue reportedly around $50 billion, lower than market expectations, concerns have spread that the pace of monetization may not meet expectations given the massive capital being poured into AI infrastructure. Broadcom's CEO's remarks, likening the market sentiment to a 'casino' and pointing to capital raising as the biggest constraint hindering AI expansion, further heightened caution across technology stocks. Additionally, China's ChangXin Memory (CXMT) announced plans to release server DDR5 with 4F² architecture within the year, adding to the perception that memory supply expansion and increased competition could become a reality. Despite Korean companies maintaining an overwhelming position in the HBM market, concerns that the pursuit of Chinese companies in general-purpose server memory could put pressure on pricing power and margins stimulated foreign selling. Even though CXMT's actual mass production yield and customer certification are still unverified, the mere possibility of a narrowing technology gap shook investor sentiment.

Exchange rate factors are also a significant variable driving foreign selling. As the won-dollar exchange rate, which rose to the 1,550 won range in the first half, fell to around 1,340 won in the second half, foreign investors saw increased dollar-denominated valuation gains, strengthening the incentive for profit-taking. The increase in dollar supply due to strong semiconductor exports is behind the won's strength, but in the stock market, this paradoxically accelerated foreign selling. The weakening of downside support as Samsung Electronics and SK Hynix's large-scale share buybacks neared completion also exacerbated the supply-demand gap. As the effect of share buybacks, which were recorded as net purchases by other corporations and absorbed selling volume, disappeared, the pressure from foreign selling was directly reflected in the index.

The forces driving the stock price decline are clearly foreign investors, especially global funds and institutions. Program trading and non-arbitrage selling in the futures market amplified volatility, and purchases by individuals and some institutions were insufficient to absorb the volume. There's no need to interpret their intentions conspiratorially. Global portfolio rebalancing and risk management are key. It's more appropriate to view this as a process where funds that had an excessively large proportion of Korean semiconductors at the beginning of the AI rally are reducing their holdings and moving capital to design and platform-centric companies like US big tech or Nvidia, or to assets that appear to have relatively lower competitive risk. While Korean companies benefit from AI demand as memory suppliers, as uncertainties regarding the sustainability of that demand and the competitive landscape emerged, a re-evaluation is taking place, concluding that 'earnings are good, but the outlook beyond next year is unclear.' The fact that Samsung Electronics' foreign ownership has fallen to the 46% range, approaching the level of the 2008 financial crisis, reflects this trend. This is the result of the ownership percentage, which had risen to the 52% range at the beginning of the year, steadily decreasing due to Middle East risks and subsequent continuous selling.

The possibility of an upturn in the Korean stock market in the second half (the remaining period from now until the end of the year) is limited but not entirely closed. In the short term, as long as foreign selling continues and AI uncertainties are not resolved, the key is whether the 6,000-point level can be sustained, with some even anticipating a further decline to the 5,600-point range. However, fundamentals remain solid. Strong memory prices and AI infrastructure investment continue, export performance is robust, and the overall KOSPI earnings outlook is being revised upwards. Yuanta Securities and others predict a 'lower first half, higher second half' trend for the KOSPI next year, suggesting 6,000-10,000 points in their base scenario and up to 12,000 points in their optimistic scenario.

The key variable is the point at which the sustainability of AI facility investment is confirmed by actual performance, and foreign supply and demand reverse as the perception that concerns about Chinese competition were excessive spreads. JPMorgan's maintenance of an overweight opinion on the Korean stock market and its view of AI as a core driver is also positive from a mid-to-long-term perspective. However, the remaining second half of 2026 is likely to be a volatile 'review phase' depending on US CPI, earnings season, and interest rate movements. The basis for re-breaking the 7,000-point mark can only be laid if a scenario where semiconductor large-cap earnings consensus is further upgraded, US interest rate burdens are eased, and foreigners start buying again is realized.

The difficulty of foreign capital inflow into the domestic market goes beyond short-term catalysts and is intertwined with structural factors. First, within the AI value chain, Korean companies are primarily perceived as memory suppliers, while US companies dominate design, software, and platforms, leading to differentiated evaluations of growth quality and sustainability. The perception that the memory industry is cyclical and the possibility of China catching up technologically lead global capital to seek 'safe AI benefits' in the US market. Second, the strong won makes foreigners who have realized exchange rate gains hesitant to re-enter. Unless the exchange rate stabilizes or turns weaker, there is little incentive for funds that have already realized profits to re-enter. Third, the vacuum of buying entities due to the end of share buybacks and market concentration (two semiconductor stocks account for nearly half of the index's weight) amplify supply and demand shocks.

As foreigners' tendency to sell in order of market capitalization strengthens, a structure where large-cap-led declines lead to an overall index decline is becoming entrenched. Finally, global capital tends to maintain a conservative weighting in Korea, observing the relative underperformance of the Korean stock market, which has seen a significant correction from its peak while the US stock market has reached new highs. Compared to the relatively strong performance of the Taiwan Weighted Index, the vulnerability of the Korean market's supply and demand is further highlighted.

The current foreign selling is a complex result of AI monetization uncertainty, China competition risks, profit-taking due to a stronger won, and global portfolio rebalancing. The fact that strong earnings are not protecting stock prices is because the market prioritizes 'future sustainability' over 'past performance.' A rebound in the second half of the year requires a shift in foreign investor sentiment, which depends on the robustness of AI demand and the easing of competitive concerns. While short-term volatility is inevitable, if the structural competitiveness and earnings growth of Korean semiconductors are confirmed, there remains room for a mid-term valuation re-rating. The key lies in when and by what catalyst the supply-demand balance will shift back towards buying. As foreign selling goes beyond simple profit-taking and takes on the character of a structural re-evaluation, the timing and conditions of that re-evaluation will determine the direction of the index until the end of the year.