South Korean stocks and won gained, as Lee Jae-myung’s widely-expected win in the presidential election ended a months-long political leadership vacuum. The nation’s stock benchmark Kospi jumped 1.5%.

South Korea's voters cast their ballots in a snap presidential election sparked by the impeachment of Yoon Suk Yeol.

Mr. Lee cruised to victory on Tuesday after his predecessor pitched the country into chaos with a brief declaration of martial law.