The KOSPI rose more than 7 percent in early trade on Thursday, reclaiming the 8,300 level. Improved investor sentiment after overnight strength in U.S. stocks, along with gains in large semiconductor shares such as Samsung Electronics and SK Hynix, was driving the index higher.

As of 9:13 a.m., the KOSPI was up 593.74 points, or 7.65 percent, at 8,357.69. The index opened up 499.90 points, or 6.44 percent, at 8,263.85.

On the previous day, the KOSPI closed up 33.13 points, or 0.43 percent, at 7,763.95. Volatility has increased recently as the market repeated sharp falls and sharp rebounds, but on Thursday it quickly reclaimed 8,000 after the open and then climbed to 8,300.

During the surge, a buy-side car was triggered in the main board market for the first time in 3 sessions. The Korea Exchange halted the effectiveness of program buy orders on the main board for 5 minutes at 9:06:02 a.m. due to a sharp rise in KOSPI200 futures prices.

At the time of the trigger, the futures price stood at 1,332.00 points, up 95.95 points, or 7.76 percent, from the benchmark price of 1,236.05 points.

By investor type, retail investors and institutions were net buyers of 34.0 billion won and 39.7 billion won, respectively. Foreigners were net sellers of 60.5 billion won.

Most top market-cap stocks were higher. Samsung Electronics was trading up 34,000 won, or 11.37 percent, at 333,000 won. SK Hynix was up 199,000 won, or 9.47 percent, at 2,300,000 won, well above the 2,000,000-won level.

SK Square was also up 11.32 percent and Samsung Electro-Mechanics was gaining 10.14 percent. Hyundai Motor was up 6.03 percent, LG Energy Solution 4.94 percent, Samsung Life Insurance 8.77 percent, Samsung C&T 10.37 percent and HD Hyundai Heavy Industries 2.79 percent.

The strength in domestic stocks on Thursday is seen as reflecting gains in U.S. stocks overnight. As technology and semiconductor shares rose in the U.S. market, buying has also flowed into large domestic semiconductor stocks that recently posted steep declines.

The Kosdaq was also surging early in the session. At the same time, the Kosdaq was up 33.55 points, or 3.37 percent, at 1,030.48. The index, which closed at 996.93 the previous day, regained the 1,000 level in a day.

In the Seoul foreign exchange market, the won was trading at 1,521.80 per dollar, down 2.80 won from the previous session.