South Korean shares breached the 2,300-point mark for the first time ever as foreign investors scooped up major tech stocks amid sound corporate earnings, bucking overnight gains on Wall Street, analysts said. The Korean won sharply rose against the US dollar.

The benchmark Korea Composite Stock Price Index added 15.55 points, or 0.68 percent, to an all-time high of 2,304.03.

Trade volume was slim at 334.55 million shares worth 5.74 trillion won ($5.04 billion), with advancers outnumbering losers 465 to 337.

Foreigners bought a net 28.8 billion won worth of stocks, extending their buying spree to a fifth day, while institutions and individuals were net sellers by offloading 25.9 billion won and 8.9 billion won, respectively.

The broad index bucked overnight gains on Wall Street. The Dow Jones industrial average rose 0.69 percent, with the tech-heavy Nasdaq composite index climbing 0.47 percent.

"The US stocks gained on the back of the improved corporate structure despite political uncertainties surrounding US President Trump. The local index is forecast to keep an upward momentum, but the increase will be limited due to uncertainties surrounding US politics," said Seo Sang-young, an analyst at Kiwoom Securities.

Most large-cap stocks were mixed across the board, with tech shares leading the gain.

Top cap Samsung Electronics ended at 2,255,000 won, up 0.85 percent from the previous session's close to snap a three-day losing streak.

Smaller rival LG Electronics added 0.25 percent to 81,600 won to hit a record high. Global chipmaker SK hynix also jumped 3.32 percent to 56,000 won.

Brokerage houses widely gained ground on rosy forecasts that the Kospi will continue to rise. Major brokerage house Mirae Asset Daewoo Securities added 0.6 percent to 9,720 won.

Auto shares were mixed with automaker Hyundai Motor remained unchanged at 170,000 won. Its sister company, Kia Motors, added 0.64 percent at 39,050 won, and top auto parts maker Hyundai Mobis edged up 0.55 percent to 274,500 won.

The local currency closed at 1,118.60 won against the US dollar, up 8.6 won from Friday's close. 

Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys added 1.4 basis points to 1.685 percent and the return on the benchmark five-year government bonds gained 2.6 basis points to 1.901 percent.(Yonhap)