The decline in the South Korean stock market is the largest since the 2008 financial crisis and comes despite trading being halted for part of the day.
The Seoul Stock Exchange was last year's big winner, with an increase of over 70 percent. However, its largest players are technology companies, which are now disadvantaged by logistical challenges in the Strait of Hormuz and soaring energy prices.
"The movements are too extreme, it feels almost impossible to make forecasts - analyses don't help much," says An Hyungjin, CEO of fund manager Billionfold in Seoul.
Other leading Asian stock exchanges are also down sharply. The Tokyo Stock Exchange's Nikkei 225 index fell 3.6 percent in late trading.
