An electronic board at a Hana Bank dealing room shows the Kospi at 6,347.76 points on Friday morning. (Yonhap) Seoul stocks surged by double digits shortly after Friday's opening, triggering buy-side trading curbs on both the Kospi and Kosdaq indexes within minutes.As of 9:20 a.m., the Kospi was trading nearly 13 percent higher at 6,313 points, remaining in double-digit territory after climbing as much as 14 percent to an intraday high of 6,386.05.The benchmark opened 1.15 percent higher at 5,657.79, before rapidly advancing past 6,300.A buy-side sidecar was activated at 9:06 a.m., suspending program trading for five minutes. A similar curb was triggered on the Kosdaq, which was trading around 7.1 percent higher at 691 after touching an intraday high of 693.81.The rebound was fueled by strong gains on Wall Street overnight, where technology stocks rallied on upbeat Microsoft earnings. The Nasdaq jumped 2.78 percent and the S&P 500 gained 1.66 percent, while the Philadelphia semiconductor index soared 8.2 percent, lifting sentiment toward Korean chip heavyweights.On the Kospi, Samsung Electronics surged as much as 25 percent to 260,000 won ($182), while SK hynix soared 28.3 percent to 1,322,000 won. Related stocks also rallied sharply, with SK Square, SK hynix's largest shareholder, jumping more than 30 percent.Meanwhile, foreign investors drove the rally, buying a net 4 trillion won of Kospi shares within just 20 minutes. Retail investors were net sellers of 3.5 trillion won, while institutions offloaded some 500 billion won.