Kospi Jumps 8% as Chip Stocks Rally on Iran Deal Hopes

South Korean stocks jumped 8% on Friday. The Kospi Index surged as much as 8% in early trading after President Donald Trump said the US was nearing an agreement with Iran to end the war. Chipmakers led the advance.

Samsung Electronics Co. and SK Hynix Inc each rose more than 9%. The two stocks now account for more than half of the Kospi's market capitalization. That concentration has made the index prone to outsized swings. Leveraged exchange-traded funds linked to Samsung and SK Hynix have grown in popularity, amplifying daily moves.

The Korea Exchange briefly halted program buying in Kospi futures as the rally accelerated. This week's volatility has been extreme. On Monday, the exchange triggered a 20-minute circuit breaker after a sharp selloff. Friday's surge was the latest in a series of sharp reversals that have defined South Korea's $4.3 trillion stock market this year.

Trump abruptly pulled back threatened military strikes against Iran earlier in the week, sparking a rally in Wall Street and risk assets more broadly. The Kospi was one of the biggest regional winners on Friday.

The fundamental outlook for Korea's memory chip sector remains strong, said Indrani De, global head of investment research at FTSE Russell. “Samsung and SK Hynix dominate the high bandwidth memory market,” she said. “Their position in memory semiconductors is hard to replace anytime soon.”