Seoul — August 05, 2026. Published after the market close; index and exchange-rate levels are official closing values, while individual-stock percentage moves cited below are intraday figures unless noted otherwise.
The 30-second version
- The KOSPI closed at 6,598.26, up 3.76%, after touching 6,674 intraday. The KOSDAQ rose 2.42% to 799.59, its fourth straight gain.
- Buying was so intense at the open that a buy-side sidecar — a five-minute pause on program trading — was triggered at 9:24 a.m., the 22nd this year.
- Foreign investors were net buyers of roughly 1.45 trillion won (about $1.0 billion) as of an early-afternoon snapshot; retail investors sold about 1.66 trillion won.
- Twelve KOSPI stocks hit their daily limit-up — the first double-digit day since records began in June 2022. SK Hynix and SK Square were among them.
- The catalyst: an overnight AI-driven rally in New York, capped by Palantir’s 93% year-over-year revenue jump and a 29% single-day surge.
An AI chip rally imported from New York
Today’s move was, at its core, Seoul pricing in what happened in New York the night before. On Tuesday (Aug 4, US time), the S&P 500 rose 1.79% to 7,736.52 — its first record close since June — while the Nasdaq jumped 2.59% and the Dow gained 1.71%, according to Global Economic’s session recap. Two stories drove it: Palantir’s second-quarter revenue grew 93% year over year (roughly 2.77 trillion won), sending its stock up 29%, and reports of memory chips selling out early reinforced the AI supercycle narrative. Meanwhile WTI crude for September delivery fell 5.7% to $75.77 a barrel after US Treasury Secretary Bessent signaled a possible deal to keep the Strait of Hormuz open and ease Iran-Israel tensions — cheaper oil being a tailwind for energy-importing Korea.
Korea sits at the center of the AI memory supply chain, so the reaction was violent. (The individual-stock percentages in this paragraph are all intraday figures, not official closes.) SK Hynix, the flagship AI memory play, closed limit-up after trading up 7-9% intraday, dragging its holding company SK Square to the limit as well. Samsung Electro-Mechanics gained 10-13% intraday on AI component demand, LG Innotek rose 15.05%, and Samsung Electronics added roughly 2.4-4.6%. The strength spread beyond chips: Samsung C&T rose 6.05% and Hyundai Motor 3.60%, while on the KOSDAQ, biotech names Alteogen (+5.81%) and HLB (+4.95%) joined in. The buying was fierce enough to trip the sidecar mechanism minutes after the open, when mini-KOSPI 200 futures spiked 5.12% — think of a sidecar as a brief speed bump that halts automated program orders for five minutes when futures move too fast.
Foreigners bought, locals sold — and kept paying down debt
One caveat on the flow data: the exchange’s final confirmed figures were not available at publication, so the numbers below are an intraday snapshot as of 1:25 p.m., as reported by E-Today (index levels in this post are official closes). At that point, foreign investors had bought a net 1.45 trillion won (about $1.0 billion at today’s rate), accelerating sharply from 387.4 billion won at 10 a.m. Institutions added 173.5 billion won. Retail investors went the other way, dumping 1.66 trillion won (about $1.2 billion) — a mix of profit-taking and forced unwinding of bearish bets.
That retail selling fits a broader pattern. Over the past month, margin lending — money retail investors borrow from brokers to buy stocks — has shrunk by 8.4 trillion won (roughly $5.9 billion), and investor deposits at brokerages have fallen to the 104-trillion-won range. In plain terms: even as the index rallies, Korean retail investors have been paying down debt rather than adding risk. That deleveraging is healthy for stability, but it also means less dry powder to fuel the next leg up.
Twelve limit-ups and a 60% inverse wipeout: signs of froth
Korean stocks cannot move more than 30% in a single day — when one hits that ceiling, it is “limit-up” and effectively stops trading higher. Today, twelve KOSPI stocks hit limit-up, the first time the count has exceeded ten since this statistic began being tracked in June 2022. Small and mid-cap optical-communication component makers joined the large caps at the ceiling. That kind of clustering is a classic sign of crowding, and it raises the odds of sharp volatility if sentiment turns.
The flip side of the squeeze was brutal for bears: an inverse product betting on an SK Hynix decline collapsed roughly 60% in a single day. Forced covering of those positions likely added mechanical buying pressure on the way up — meaning some of today’s gain reflects positioning, not fresh conviction. Two other risks are worth keeping in view: the oil-price drop rests on a Hormuz deal that has not actually been concluded, and the fact that retail investors sold over a trillion won into the rally suggests domestic confidence has not fully recovered.
Key closing numbers
| Item | Close | Change | Note |
|---|---|---|---|
| KOSPI | 6,598.26 | +3.76% | Intraday high 6,674; buy sidecar at 9:24 a.m. |
| KOSDAQ | 799.59 | +2.42% | Fourth straight daily gain |
| USD/KRW | 1,424.38 | -0.29% | Won stronger |
| Foreign net buying | +1.45 trillion won | — | Intraday snapshot, 1:25 p.m.; not exchange-final |
| Retail net selling | -1.66 trillion won | — | Same snapshot |
| WTI (Sept) | $75.77 | -5.7% | Overnight, on Hormuz de-escalation hopes |
What to watch next
- The 6,600 and 7,000 levels: local analysts are already discussing whether this rebound sets up a retest of KOSPI 7,000 after the recent whipsaw stretch.
- Final exchange flow data: confirmation of whether foreign buying held its pace into the close.
- Follow-through after the limit-up cluster: whether today’s twelve capped stocks extend gains or mean-revert — an unusually crowded day often invites profit-taking.
- The Hormuz negotiations: if the deal Bessent hinted at stalls, oil and market volatility could snap back.
- Retail behavior: whether deposits and margin balances keep shrinking, which would cap the rally’s domestic fuel.
FAQ
Why did the KOSPI rise almost 4% today?
A record-setting overnight session on Wall Street — driven by Palantir’s 93% revenue surprise and AI memory demand — flowed directly into Korea’s chip-heavy market. Foreign investors bought roughly 1.45 trillion won of stock intraday, and forced covering of bearish bets added fuel.
What is a sidecar in the Korean stock market?
A sidecar is a circuit-breaker-lite: when KOSPI 200 futures move 5% or more and hold there, program (automated) trading is paused for five minutes to let the market catch its breath. Today’s was triggered by buying, not selling — the 22nd activation this year.
What does limit-up mean in Korea?
Korean exchanges cap single-day price moves at 30%. A stock that rises the full 30% is “limit-up” and cannot trade higher that day. Twelve KOSPI stocks hit the cap today — a first since tracking began in June 2022.
Are foreign investors buying Korean stocks?
Yes — heavily, at least by the intraday count. As of 1:25 p.m., foreigners were net buyers of about 1.45 trillion won (roughly $1 billion), while domestic retail investors were net sellers and continued reducing margin debt, which has fallen 8.4 trillion won in the past month.
Sources
- Global Economic — US index closes (S&P 500, Dow, Nasdaq), Palantir’s results and 29% surge, and the WTI move.
- CBC News — KOSPI/KOSDAQ closing levels and the USD/KRW exchange rate.
- E-Today — the intraday investor-flow snapshot (foreign, institutional, and retail net figures).
- Hankook Ilbo — the buy-side sidecar activation and futures spike.
- MBC News — the twelve limit-up count and the roughly 60% inverse-product collapse.
- Herald Business — margin-lending and investor-deposit trends.
- Asia Economy — analyst discussion of a KOSPI 7,000 retest.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.