[DigitalToday reporter Sangyeop Oh] The KOSPI rose more than 1,000 points after falling for three straight sessions, posting the biggest gain on record in both percentage terms and points. As investor sentiment recovered on a surge in U.S. technology and semiconductor shares, foreign and institutional buying concentrated in Samsung Electronics and SK Hynix.

On July 31, the KOSPI closed up 1,001.89 points, or 17.91 percent, at 6,595.45. Both the percentage gain and point rise were the largest on record at the close. The previous biggest percentage gain was 11.95 percent on Oct. 30, 2008, and the biggest point rise was 612.52 points on June 9.

The KOSPI opened up 64.23 points, or 1.15 percent, at 5,657.79 and quickly widened its gains. The intraday low was 5,629.76 and the high was 6,630.77.

In the main market, foreigners were net buyers of 71.8 billion won and institutions bought a net 11.8 billion won. Retail investors were net sellers of 82.5 billion won, unloading holdings during the sharp rebound.

The KOSDAQ also ended up 74.98 points, or 11.63 percent, at 719.76. The gain was the second-highest on record for the KOSDAQ.

In both markets, a buy-sidecar was triggered shortly after the open, halting the effectiveness of program buy orders for 5 minutes.

In the main market, the buy-sidecar was triggered at 9:06:02 a.m. when KOSPI 200 futures rose 14.97 percent from the benchmark price. In the KOSDAQ market, a buy-sidecar was triggered at 9:06:03 a.m. as KOSDAQ 150 futures rose 9.33 percent and the KOSDAQ 150 climbed 7.91 percent.

Large semiconductor stocks led the rebound. SK Hynix closed up 396,000 won, or 29.95 percent, at 1,718,000 won, rising to the daily limit.

It was the first time SK Hynix hit the daily upper limit under the current 30 percent price-limit system. Its previous biggest percentage gain was 15.91 percent on June 9.

Samsung Electronics also finished up 55,500 won, or 26.81 percent, at 262,500 won. That was its biggest percentage gain on record, beating the previous mark of 15 percent on Dec. 5, 2001. SK Square and Samsung Electro-Mechanics jumped 29.91 percent and 29.92 percent, respectively, nearing their daily upper limits.

Hyundai Motor rose 10.54 percent to 388,000 won and Samsung Life Insurance gained 17.99 percent to 311,500 won. LG Energy Solution rose 2.50 percent and KB Financial Group gained 0.66 percent. Samsung Biologics fell 2.75 percent.

The rebound in South Korean shares was influenced by strength in U.S. big tech and semiconductor stocks. As the U.S. June personal consumption expenditures (PCE) price index matched market expectations, Microsoft and Amazon outlined plans for cloud business growth and expanded investment in artificial intelligence, easing worries about slowing semiconductor demand.

In the U.S. market overnight, Micron rose 18.36 percent and AMD climbed 13.00 percent. The Philadelphia Semiconductor Index also gained 8.19 percent. Expectations that forced selling of semiconductor stocks by global leveraged funds was nearing an end also helped improve supply and demand.

Han Ji-young (한지영), a researcher at Kiwoom Securities, said, "Considering the possibility that global semiconductor deleveraging is ending, big tech companies expanding capital spending, and the excessive decline in stock prices and valuations, we are moving into a phase where upside factors are dominant."