Boosted by blockbuster earnings from global AI bellwether Nvidia, Samsung Electronics and SK Hynix, which surged temporarily in early trading on the 27th, finished the regular trading session up by 1% and 2%, respectively.

On the main bourse that day, Samsung Electronics closed at 266,000 won, up 1.72% from the previous session.

Starting sharply higher at 270,000 won, up 3.25%, Samsung Electronics momentarily dipped to 262,500 won (+0.38%) during the morning session.

SK Hynix also finished up 2.49% from the previous session at 1,730,000 won.

SK Hynix similarly soared to 1,788,000 won (+5.92%) right after the market opened before giving back a portion of its gains.

Nvidia's revenue for the second quarter of fiscal 2027 (May to July), disclosed early that day in Korean time, jumped 106% year-on-year to reach 96.22 billion dollars (approx. 133.2 trillion won).

This figure exceeded the consensus (market average forecast of 92.27 billion dollars) compiled by London Stock Exchange Group (LSEG) and others by about 4 billion dollars.

In particular, data center revenue came in at 89 billion dollars, surpassing the expected 85.8 billion dollars.

Earnings per share (EPS) surged 119.8% to 2.22 dollars, significantly beating the consensus of 2.09 dollars.

Nvidia projected that this robust performance would continue going forward, driving its fiscal 2028 annual revenue growth rate to reach 70%, well ahead of the market expectation of 44.8%.

As a result, U.S. AI and semiconductor-related stocks—including Nvidia, Micron, and SK Hynix American Depositary Receipts (ADRs)—surged in after-hours trading, and this sentiment appeared to carry over into the domestic stock market.

However, the stocks that had surged in early trading quickly narrowed their gains, which appears to have been influenced by the Bank of Korea raising its benchmark interest rate by 25 bps during the Monetary Policy Committee meeting that day, alongside caution ahead of the keynote speech by Federal Reserve Chair Kevin Warsh at the Jackson Hole symposium scheduled for 11:00 p.m. on the 28th in Korean time.

A significant expansion in net selling by retail investors amid a supply-and-demand vacuum from foreign investors also served as a backdrop for the narrowing gains.

On the main bourse that day, foreigners and institutions were net buyers, purchasing 152.4 billion won and 177.6 billion won, respectively.

Retail investors alone were net sellers, offloading 1.9149 trillion won.

In the Kospielectrical and electronic sector—to which Samsung Electronics and SK Hynix belong—foreigners and institutions held an advantage with net purchases of 365.9 billion won and 289.5 billion won, whereas retail investors held a selling advantage of 2.2338 trillion won.

Meanwhile, net purchases in the Kospielectrical and electronic sector by other corporations, which have recently shown a large increase trend driven by SK Hynix's large-scale treasury stock buyback and retirement, were tallied at 1.5903 trillion won.

On the other hand, Samsung Electronics and SK Hynix ranked first in foreign net purchases and first in foreign net sales, respectively, that day.

Foreigners net bought 374.7 billion won worth of Samsung Electronics shares, while net selling 262.2 billion won worth of SK Hynix.

(Photo: Yonhap News)