Seoul shares sharply up late Wednesday morning on US-Iran ceasefire

An electronic board in the dealing room of Hana Bank in Seoul shows the benchmark KOSPI and KOSDAQ indices, Wednesday. Yonhap

Korean stocks rose sharply higher late Wednesday morning as the United States and Iran agreed on a two-week ceasefire and reopening the Strait of Hormuz.

The benchmark Korea Composite Stock Price Index (KOSPI) rose 326.12 points, or 5.94 percent, to 5,820.9 as of 11:20 a.m.

The bourse operator activated a buy-side sidecar, temporarily halting program-driven buy orders in KOSPI futures earlier in the session.

U.S. President Donald Trump said in a social media post that the U.S. would suspend attacks on Iran for two weeks if Tehran agrees to the "complete, immediate and safe opening" of the crucial strait.

In response, Iran's foreign ministry released a statement accepting the ceasefire proposal, noting "safe passage" through the crucial waterway "will be possible via coordination with Iran's Armed Forces and with due consideration of technical limitations."

Market bellwether Samsung Electronics surged 7.12 percent, and chip giant SK hynix soared 9.5 percent.

Builders traded higher on potential reconstruction opportunities in Iran, with Daewoo Engineering & Construction rising 27.95 percent and Hyundai Engineering & Construction increasing 13.34 percent.

Oil refiners lost ground as global crude prices fell sharply following the ceasefire, with SK Innovation losing 2.96 percent and S-Oil sliding 2 percent.

Defense shares were among losers as well, with Hanwha Aerospace moving down 5.14 percent and Hyundai Rotem surrendering 3.32 percent.

The local currency was trading at 1,478.8 won against the greenback at 11:20 a.m., up 25.4 won from the previous session.