[DigitalToday reporter Sang-yeop Oh] South Korea's KOSPI jumped more than 3 percent on the back of about 1.4 trillion won in net foreign buying. The index climbed to the 6,670 level during the session, triggering a buy-sidecar, as semiconductor and information technology heavyweights such as Samsung Electronics and SK Hynix advanced.

On Tuesday, the KOSPI closed up 239.31 points, or 3.76 percent, at 6,598.26. The index opened up 244.53 points, or 3.85 percent, at 6,603.48, before giving back part of its gains in the afternoon and finishing just short of the 6,600 level.

In the main board market, foreign investors led the rise with net purchases of 1.45 trillion won. Retail and institutional investors were net sellers of 1.18 trillion won and 283.8 billion won, respectively.

A buy-sidecar was also triggered early in the session. At 9:24:56 a.m., KOSPI200 futures rose 5.12 percent from the reference price, halting the effectiveness of program buy orders in the main board market for 5 minutes. It was the first KOSPI buy-sidecar in 3 trading sessions since July 31.

Most top market-cap stocks also rose.

Samsung Electronics ended up 2.50 percent at 246,000 won, and SK Hynix rose 5.77 percent to close at 1,668,000 won.

SK Square gained 5.57 percent to 1,119,000 won. Samsung Electro-Mechanics jumped 14.43 percent to end at 1,356,000 won, the biggest rise among the top market-cap stocks.

Hyundai Motor rose 3.06 percent, LG Energy Solution gained 2.13 percent and Samsung Biologics was up 1.02 percent. Samsung Life climbed 5.76 percent and KB Financial rose 1.13 percent.

The KOSDAQ closed up 18.87 points, or 2.42 percent, at 799.59. It moved above 800 during the session but finished slightly below that level.

In Seoul's foreign exchange market, the won was at 1,425.80 per dollar, up 5.20 won from the previous session.

Strength in semiconductor shares in the U.S. market overnight also affected local stocks. The Philadelphia Semiconductor Index surged 6.55 percent, while Micron and AMD rose 7.62 percent and 7.00 percent, respectively. A fall in international oil prices and U.S. Treasury yields on expectations for U.S.-Iran talks also supported investor sentiment.

Han Ji-young (한지영), an analyst at Kiwoom Securities, said demand is shifting to oversold names as the KOSDAQ's drop from its recent high was larger than the KOSPI's through the end of last month and as a decline in margin debt has eased selling pressure.

Han added it was not so much a full shift in leadership to small and mid-caps as a process of narrowing the return gap between large-cap and small- and mid-cap shares.