[DigitalToday reporter Oh Sang-yup] Sidecar curbs were triggered in South Korea's stock market throughout all five sessions this week, as the KOSPI and Kosdaq tumbled more than 5 percent.

The KOSPI ended on July 24 down 406.27 points, or 5.72 percent, at 6,690.62. It opened down 96.11 points, or 1.35 percent, at 7,000.78 from the previous session. Losses later widened and the index slipped to the 6,600 level.

In the domestic market this week, a sell sidecar was triggered on July 20, followed by buy sidecars from July 21 to 23, before another sell sidecar was triggered on the day.

A sell sidecar was triggered on the main board at 11:23 a.m. At the time, mini KOSPI200 futures were down 5.04 percent from the reference price. Sidecar triggers in the main board this year rose to 41 in total, including 20 buy triggers and 21 sell triggers.

In the main board, foreigners sold a net 3.2685 trillion won and institutions sold a net 1.9514 trillion won. Retail investors bought a net 5.1783 trillion won, absorbing supply.

Most of the top market-cap stocks fell sharply.

Samsung Electronics closed down 20,500 won, or 7.59 percent, at 249,500 won. SK Hynix fell 160,000 won, or 8.34 percent, to 1,759,000 won.

SK Square fell 9.17 percent, Samsung Electro-Mechanics dropped 8.43 percent, Hyundai Motor slid 7.18 percent, LG Energy Solution fell 5.32 percent, Samsung Life Insurance lost 3.49 percent and KB Financial Group dropped 2.72 percent.

Samsung Biologics, meanwhile, rose 10.08 percent to end at 1,518,000 won, outperforming other top market-cap names.

The Kosdaq ended down 42.06 points, or 5.32 percent, at 748.22.

A sell sidecar was triggered in the Kosdaq market at 11:47 a.m. At the time, Kosdaq 150 futures fell 6.09 percent and the Kosdaq 150 slid 5.90 percent. Sidecar triggers in the Kosdaq market this year total 25, including 14 buy triggers and 11 sell triggers.

In Seoul's foreign exchange market, the won ended at 1,466.80 per dollar, down 9.70 won from the previous session.

The sharp fall in domestic stocks is seen as reflecting a steep drop in U.S. big tech shares the previous day and rising international oil prices and U.S. Treasury yields amid geopolitical instability in the Middle East.

Alphabet fell 7.13 percent and Tesla plunged 14.52 percent. The Nasdaq fell 2.15 percent, the Standard & Poor's 500 dropped 1.21 percent and the Dow Jones fell 0.97 percent. U.S. West Texas Intermediate crude rose 6.17 percent to $92.19 a barrel.

Han Ji-young (한지영), a researcher at Kiwoom Securities, said geopolitical uncertainty and a plunge in U.S. stocks put downward pressure on domestic shares. He said, however, that the KOSPI's valuation burden is lower than during past periods of surging interest rates and that expectations for semiconductor earnings remain, limiting the downside.