[Edaily Reporter PARK MIN ] On the 7th, SamsungElectronics(005930)and SK hynix(000660)posted significant gains in the 5–8% range, buoyed by expectations of increased memory demand driven by OpenAI’s next-generation artificial intelligence (AI) model, “GPT-6 Astra.” Foreign and institutional investors, who had been selling off shares for some time, jointly made net purchases totaling around 5 trillion won, raising hopes for a rebound in the stock market, which had been stuck in a trading range.

However, there are also growing calls to guard against premature optimism, as stock price volatility has increased due to trading volumes shrinking to record lows following last July’s historic market downturn. Experts predict that the direction of the domestic stock market will not be determined until macroeconomic issues—such as the U.S. inflation index release and the Federal Open Market Committee (FOMC) regular meeting scheduled for mid-month—have passed.

◇SK hynix Up 8%, SamsungElectronics Up 5%

According to MP Doctor on the 7th, SK hynix closed at 1,783,000 won, up 8.26% from the previous trading day, while SamsungElectronics closed at 270,000 won, up 5.68% from the previous trading day. Buoyed by the strength of these two market leaders, the KOSPI also rose 308.18 points (4.61%) from the previous trading day, closing at 6,995.39—just shy of the 7,000 mark.

In particular, foreign investors purchased 2.5525 trillion won worth of stocks on the KOSPI, while institutional investors bought 2.6496 trillion won worth, resulting in a total net buying volume of 5.2 trillion won that drove the index higher. Share buybacks by the top two semiconductor companies—which have been ongoing since late last month—and net buying by other corporations continued today as well, with purchases totaling 1.6352 trillion won, further driving the index higher.

Previously, both companies had been trading in a narrow range, fluctuating up and down, following a historic market crash in July. SK hynix recorded a sharp one-day rebound on August 20—the day after its unprecedented shareholder return plan was announced (SK hynix up 12.73%, SamsungElectronics up 9.49%)—but has since remained trapped within a trading range, fluctuating up and down before now attempting to break through the upper boundary once again.

Some analysts in the securities industry point out that since this rebound by the two leading semiconductor stocks occurred amid a “liquidity drought” that has driven KOSPI trading volume to its lowest level this year, it is unlikely to lead to a sustained “breakout above the upper boundary of the trading range.” In fact, while the KOSPI was on a relentless rally, breaking through the 9,000 mark last June, the average daily trading volume exceeded 50 trillion won; however, it has plummeted to 17 trillion won this month. This means trading volume has shrunk to less than half of what it was just over two months ago. Furthermore, investor deposits—which serve as standby funds for the stock market—plummeted to the 96 trillion won range at the end of August, remaining at their lowest level this year, and are cited as a factor constraining the index’s resilience.

◇ U.S. August CPI, PPI, and FOMC Meetings Coming Up in Quick Succession

Another source of concern is that this month is a “Big Week,” packed with global macroeconomic events that influence the domestic stock market. Following the release of the U.S. Producer Price Index (PPI) and Consumer Price Index (CPI) in the middle of this month, a series of major turning points in monetary policy—including the Federal Open Market Committee (FOMC) regular meeting—are scheduled to take place. In the current market environment, where trading volume is low, even a minor data shock could cause the index to fluctuate significantly.

The securities industry expects trading volume to increase and the index to rebound around the time SamsungElectronics and SK hynix announce their third-quarter earnings in late October. Lee Kyung-min, an analyst at DaishinSecurities, stated, “The domestic stock market has been on a downward trend as external uncertainties have come to the fore, despite robust export and earnings momentum in both the semiconductor and non-semiconductor sectors.” He added, “However, as earnings, economic, and policy momentum remain valid, we expect a rebound driven by a valuation re-rating.”

In particular, attention is focused on whether the “share buybacks by other corporations” will serve as a bulwark capable of weathering global turbulence. Currently, SK hynix is conducting a share buyback worth 40 trillion won, and SamsungElectronics is carrying out one worth 15 trillion won; given the current average daily purchase rate, these programs are expected to wrap up around mid-October at the earliest.

An official from the securities industry noted, “With trading volume shrinking, short-term volatility stemming from macroeconomic events in September may be unavoidable,” but added “As share buybacks by other companies provide downside support, if expanding AI memory demand and third-quarter earnings come into focus, market liquidity will recover, creating the momentum needed to break out of the trading range.”