Seoul stocks spike nearly 6 pct on chip rally, eased U.S. bond yield concerns

Seoul stocks surged nearly 6 percent on Thursday, driven by optimism surrounding chip manufacturers Samsung Electronics and SK hynix, alongside reduced concerns over U.S. bond yields. The Korean won depreciated against the U.S. dollar during the trading session. The Korea Composite Stock Price Index (KOSPI) climbed 381.41 points, or 5.89 percent, to conclude at 6,852.58, rebounding from a previous day's 6.1 percent drop triggered by a tech sell-off.

The index had plummeted around 6 percent the prior day but regained its losses after SK hynix unveiled a 40 trillion-won ($28.7 billion) share buyback program. Additionally, speculation mounted regarding Samsung Electronics' forthcoming announcement on shareholder return policies later in the month. Program trading for KOSPI-listed shares was halted for five minutes around 10 a.m., as the Korea Exchange (KRX) activated a buy-side sidecar measure when the KOSPI 200 Futures Index surged 5 percent or more within a single minute.

Overnight, major U.S. indexes recorded gains as yields on U.S. Treasury bonds fell, after the Treasury Department announced plans to significantly boost purchases of longer-term government securities. The yield on the 30-year Treasury bond, which had peaked at the highest level since 2007, declined, along with the benchmark 10-year Treasury yield.