South Korean stocks closed slightly lower on Friday, ending a three-day winning streak, as investors awaited Federal Reserve Chair Jerome Powell's speech. The benchmark Korea Composite Stock Price Index fell 0.22 percent to 2,701.69, with moderate trade volume. Foreigners sold a net 241.9 billion won worth of shares, while individuals offloaded a net 103.2 billion won, and institutions bought a net 334.6 billion won. Investors adopted a cautious approach ahead of Powell's speech, which is expected to provide insights into the Fed's monetary policy direction. Additionally, they are keeping an eye on Nvidia's upcoming earnings report for further indications of the sustainability of the momentum in tech shares. Top tech companies like Samsung Electronics and SK hynix experienced declines, while leading carmaker Hyundai Motors and its sister company Kia saw gains. The local currency also weakened against the US dollar, trading at 1,338.8 won as of 3:30 p.m.