South Korean chip stocks slumped on Aug. 19 as rising long-term government bond yields in the United States and Japan weakened investor sentiment and triggered profit-taking across semiconductor shares. Samsung Electronics fell 7.17% to 249,250 won and SK Hynix dropped 8.42% to 1.522 million won by 9:12 a.m., while Samsung Electronics preferred shares, SK Square and Samsung Life Insurance also declined sharply. The pressure followed an overnight Wall Street selloff, with the 30-year US Treasury yield rising above 5.33% on Aug. 18 to its highest intraday level since 2007 and the Philadelphia Semiconductor Index falling nearly 5%. South Korea's KOSPI had also been reported down 5% at the open, according to Bitget market data cited earlier.