Seoul: Seoul stocks ended higher for the second consecutive session Wednesday on an extended chip rally ahead of upcoming earnings releases from U.S. big tech companies. The Korean won fell against the U.S. dollar. According to Yonhap News Agency, the benchmark Korea Composite Stock Price Index (KOSPI) closed up 49.75 points, or 0.74 percent, to 6,797.7 after rising as high as 7,166.00.

The index initially opened sharply higher but lost some of its early gains as retail and institutional investors moved to lock in profits by selling off tech heavyweights. Combined, these investors sold a net 2.61 trillion won (US$1.8 billion), while foreign investors purchased a net 2.62 trillion won. Trade volume was moderate at 368.7 million shares worth 28.1 trillion won, with winners outnumbering losers 467 to 398.

Lee Kyoung-min, an analyst from Daishin Securities, commented, "The KOSPI returned some of its earlier advance in the face of rising global oil prices, and as investors took a cautious stance ahead of the earnings release from Alphabet." Alphabet, the parent company of Google, is expected to release its second-quarter earnings results Wednesday (U.S. time).

Investors remained cautious due to ongoing tensions in the Middle East and uncertainties related to Washington's global tariffs of 10 percent, which are scheduled to expire later this week. In the local market, performance among heavyweights varied. Samsung Electronics saw a slight increase of 0.58 percent to 260,500 won, while SK hynix dropped 0.33 percent to 1,830,000 won.

Robotics companies gained momentum following Samsung Electronics' announcement to strengthen its robotics business. Hyundai Motor, which owns Boston Dynamics, rose 4.76 percent to 418,000 won, and LG Electronics climbed 5.48 percent to 182,700 won. Conversely, Samsung Biologics fell 1.65 percent to 1,372,000 won, and Hanwha Aerospace declined 0.89 percent to 891,000 won.

The Korean won was quoted at 1,480.1 against the U.S. dollar, down 6.7 won from the previous session. Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys advanced 4.6 basis points to 3.913 percent, and the return on the benchmark five-year government bonds rose 5.2 basis points to 4.172 percent.