Korean Stock Market Jumps 9.6% on Samsung, SK Hynix Prices Rally

South Korea’s stock market delivered a stunning comeback on Thursday, with the benchmark Kospi staging its best day in years after a historic war‑ and oil‑driven crash earlier in the week. The index surged between 9.6% and 11% intraday, closing around 5,584 points, up 9.63% on the session after tumbling nearly 20% over the previous three days amid the Iran conflict and $80+ oil shock.

According to the Yahoo Finance, the Kospi jumped as much as 12% at the open, effectively erasing most of its worst‑ever single‑day slump from just 24 hours earlier.

The Korea Exchange even had to reactivate its “sidecar” trading curb, briefly halting program trading for five minutes as buying overwhelmed the order book, this time on the upside instead of during the selloff. Over the past month, the index is now up 8.6%, and an eye‑popping 114.5% versus the same time last year, underscoring just how violently sentiment has swung in one of the world’s most volatile major markets.

Samsung and SK Hynix Rip Higher

Tech stocks were firmly in the driver’s seat. Chip giant Samsung Electronics soared about 11-15% on the day, while SK Hynix jumped roughly 10-16%, according to various intraday prints and local media reports.

The semiconductor heavyweights, which together make up more than one‑third of Kospi’s market cap, had been hammered during the war panic but remain the core of Korea’s AI and memory supercycle story. Their rebound helped pull the entire market higher, as foreign and institutional investors swung from heavy net sellers earlier in the week to aggressive buyers on Thursday.

The junior Kosdaq index also exploded 14.1% to 1,116.41, outpacing the main board as retail investors piled back into growth and tech names that had been indiscriminately sold during the rout.​

Diplomacy Hopes and Oil Stabilization Buoy Sentiment

What changed? Hopes for diplomacy in the Iran conflict and signs of stabilizing oil prices. The Straits Times reports that renewed talks and back‑channel negotiations eased fears of a prolonged regional war, while Brent crude slipped off its $84 highs, taking some pressure off energy‑import‑dependent economies like South Korea.

Overnight gains on Wall Street added to the tailwind, giving investors confidence to buy the dip in high‑beta Korean tech stocks. For now, the Korean stock exchange has shifted from crash mode to relief rally, but volatility remains elevated.

Regulators are still ready to deploy trading curbs if swings become disorderly, and analysts caution that the Kospi’s path toward the 6,000-7,000 band will likely be bumpy as geopolitics, oil prices and AI sentiment continue to collide.