KOSPI soars more than 8% on Samsung wage agreement, Nvidia earnings beat

The KOSPI and Kosdaq indexes are displayed on the electronic board at the dealing room of Hana Bank headquarters in Seoul, Thursday. KOSPI closed at 7,815.59, up 606.64 points, or 8.42 percent, from the previous session. Yonhap

The benchmark KOSPI staged a strong rebound Thursday, rising more than 8 percent in a single session on the back of a labor agreement at Samsung Electronics and Nvidia’s better-than-expected earnings results.

The index opened at 7,486.37, up 277.42 points, or 3.85 percent, and extended gains throughout the session to close at 7,815.59, up 606.64 points, or 8.42 percent.

It was the KOSPI’s strongest daily advance in 34 trading sessions since an 8.44 percent jump on April 1 and marked the index’s sixth-largest one-day gain on record.

The KOSPI had briefly topped the 8,000 mark intraday on May 15 before tumbling amid heightened market volatility. After two straight sessions of losses, the benchmark index rebounded sharply.

Shares of Samsung Electronics also surged 8.51 percent to close at 299,500 won ($199), helping lift overall market sentiment.

The firm's management and labor unions reached a tentative wage agreement late Wednesday, preventing a planned strike at the world’s largest memory chipmaker.

Positive momentum was also fueled by overnight gains on Wall Street, particularly among chipmakers, alongside stabilizing global oil prices. The Philadelphia Semiconductor Index surged 4.49 percent ahead of Nvidia’s earnings announcement.

Following the close of regular trading, Nvidia posted quarterly results that topped market forecasts. The artificial intelligence chip giant reported first-quarter revenue of $81.62 billion, marking an 85 percent increase from a year earlier and surpassing analysts’ expectations of $78.86 billion.

A KOSPI buy-side sidecar was triggered about 24 minutes after trading began, reflecting the market’s sharp upward momentum.

The temporary trading curb is imposed when KOSPI 200 futures climb more than 5 percent above the benchmark level and hold those gains for at least one minute, halting program buy orders for five minutes.

The secondary Kosdaq market also activated a buy-side sidecar.

The tech-heavy bourse opened at 1,085.30, up 29.23 points, or 2.77 percent, and extended gains to close at 1,105.97, rising 49.90 points, or 4.73 percent, from the previous session. The sidecar was triggered at 9:27 a.m., three minutes after the KOSPI measure.

The mechanism takes effect when Kosdaq 150 futures jump more than 6 percent and the Kosdaq 150 index rises over 3 percent from the prior session’s closing level, with both conditions maintained for at least one minute.

“Investor sentiment improved after uncertainties over a possible strike at Samsung Electronics were resolved, while worries about cash outflows related to incentive payouts also eased,” said Lee Jae-won, an analyst at Yuanta Securities Korea. “Optimism over a potential end to the Iran conflict and upbeat earnings from Nvidia further fueled the market rally.”

Speaking to reporters overnight, U.S. President Donald Trump said negotiations between Washington and Tehran had entered the “final stages,” fueling expectations of a possible ceasefire deal.

The easing geopolitical tensions reduced fears that the Strait of Hormuz could be disrupted, tempering concerns over surging energy prices and sending oil prices into a sharp drop.

July Brent crude futures slid 5.63 percent to settle at $105.02 per barrel, while July West Texas Intermediate crude futures declined 5.66 percent to finish at $98.26 a barrel.

In the Seoul foreign exchange market, the Korean won opened at 1,499.5 against the U.S. dollar, improving by 7.3 won from the previous session, and finished onshore trading at 1,506.1 won, weakening by 0.7 won.