South Korea's KOSPI rose above the 6,600 level in early trading on the back of gains in U.S. technology and semiconductor shares. Foreign investors turned net buyers, while heavyweight chipmakers such as Samsung Electronics and SK Hynix were leading the index higher.

As of 9:13 a.m. on Tuesday, the KOSPI was up 281.14 points, or 4.42 percent, at 6,640.09, from the previous session. It opened up 244.53 points, or 3.85 percent, at 6,603.48.

In the main board market, foreigners were net buyers of 309.7 billion won. Retail investors and institutions were net sellers of 257.0 billion won and 31.3 billion won, respectively.

Large-cap semiconductor and information technology-related shares were strong.

Samsung Electronics was trading at 251,000 won, up 4.58 percent from the previous session, while SK Hynix rose 6.53 percent to 1.68 million won.

SK Square climbed 7.55 percent to 1.14 million won, while Samsung Electro-Mechanics jumped 11.73 percent to 1.324 million won. Hyundai Motor was up 4.08 percent, LG Energy Solution gained 3.50 percent, and Samsung Biologics and Samsung Life Insurance rose 1.56 percent and 4.50 percent, respectively. KB Financial Group added 3.91 percent.

The KOSDAQ was up 7.71 points, or 0.99 percent, at 788.43. It extended gains after rising more than 5 percent the previous day.

In the Seoul foreign exchange market, the won was at 1,428.10 per dollar, up 2.90 won from the previous session.

Overnight, a sharp rise in U.S. semiconductor shares also carried into South Korea's stock market. The Dow Jones Industrial Average rose 1.71 percent, the Standard & Poor's 500 gained 1.79 percent and the Nasdaq climbed 2.59 percent. The Philadelphia Semiconductor Index surged 6.55 percent. Micron rose 7.62 percent, AMD gained 7.00 percent and Broadcom added 6.61 percent.

Expectations of possible U.S.-Iran talks and reopening of the Strait of Hormuz grew, pushing down international oil prices and U.S. Treasury yields, which also improved investor sentiment. An assessment that demand for AI investment is translating into actual revenue through results from major big tech and AI-related companies also supported semiconductor shares.

Han Ji-young (한지영), an analyst at Kiwoom Securities, said, "An improvement in the macro environment and better momentum from the second-quarter earnings season are appearing together." She added, "Even if temporary profit-taking and increased volatility emerge, the effectiveness of a strategy to increase stock allocations is expected to remain valid."