verdict at the close
KOSPI +5.87% to 6,851.33 — semiconductor rebound erases Wednesday’s loss
The KOSPI closed at 6,851.33 on Thursday, August 20 (2026), up 5.87% on the day, as foreign investors posted net purchases of ₩1,707.9bn on the KOSPI (preliminary, collected at 15:53 KST; final figures are expected by 18–20:00 KST tonight).The KOSDAQ added +1.80% to close at 839.27, though it traded in a much narrower high–low range of 16.08 points (1.93%) compared with the KOSPI’s 304.46-point swing (4.61%); multiple catalysts were in play simultaneously and no single factor can be assigned as the sole driver.
The day’s path
A window marking the hours when direction turned during the session
KOSPI staged a full reversal of Wednesday’s −5.80% drop, closing up +5.87% at 6,851.33 with foreigners as net buyers throughout the session.
Top by trading value10— snapshot
A window on how the top trading-value names have moved up to this hour
KOSPI VWAP anchored above 6,800 through the afternoon as semiconductor heavyweights held their morning gains into the close.
| Stock | Prior close | Open | Gap | High (time) | Close | Change | Low (time) |
|---|---|---|---|---|---|---|---|
| SK hynix | 1,500,000 | — | — | — | 1,691,000 | +12.73% | — |
| Samsung Electronics | 247,500 | — | — | — | 271,000 | +9.49% | — |
| Samsung Electro-Mechanics | 1,387,000 | — | — | — | 1,396,000 | +0.65% | — |
| SK Square | 1,004,000 | — | — | — | 1,123,000 | +11.85% | — |
| Samsung Electronics (Pref.) | 173,700 | — | — | — | 191,200 | +10.07% | — |
| SK eternix | 57,800 | — | — | — | 56,000 | −3.11% | — |
| Kumho E&C | 12,600 | — | — | — | 15,650 | +24.21% | — |
| Hanwha Aerospace | 1,177,000 | — | — | — | 1,167,000 | −0.85% | — |
| NAVER | 208,000 | — | — | — | 219,500 | +5.53% | — |
| KB Financial Group | 166,407 | — | — | — | 160,000 | −3.85% | — |
The KOSPI opened at 6,672.39, dipped to its session low of 6,600.09 at 09:08, then climbed steadily through mid-morning to reach the intraday high of 6,904.55 at 13:14 before drifting into a 6,810–6,860 band through the afternoon close.Nextrade (NXT)Korea’s alternative trading system launched in 2026, operating pre-market, main, and after-market sessions alongside the Korea Exchange (KRX).NXT data (20-minute delayed during the session) provides an early cross-check on KRX prices and extends trading hours beyond the 15:30 KST regular close. data (20-minute delayed snapshot as of 15:25 KST) showed SK hynix leading alternative-venue turnover at ₩520.39bn with a quoted gain of +12.93%, consistent with the KRX close figure of +12.73%; NXT figures are not the confirmed KRX settlement and are shown for directional reference only.
Flow summary
A window on how much foreign investors, retail investors, investment firms and pension funds each bought and sold
Foreigners net bought ₩1.71tn on KOSPI today as the index surged +5.87% to close at 6,851.33, reversing Wednesday’s rout.
The stocks that moved the market — top by turnover10
A window on which investor groups backed the most heavily traded stocks
SK hynix and Samsung Electronics together drew ₩1.61tn in turnover, anchoring a session dominated by semiconductor names.
SK hynix led KOSPI turnover at ₩910.96bn (+12.73%), followed by Samsung Electronics at ₩696.07bn (+9.49%), Samsung Electro-Mechanics at ₩106.28bn (+0.65%), SK Square at ₩92.76bn (+11.85%), and Samsung Electronics preferred at ₩67.42bn (+10.07%).On KOSDAQ, Alteogen topped turnover at ₩33.67bn (+11.86%), while Kolon TissueGene drew ₩17.81bn despite falling −16.41%, and HPSP registered ₩25.14bn at +5.03%.
| Stock | Close | Change | Turnover | Foreign investors | Institutions | Investment firms | Pension funds | Retail investors |
|---|---|---|---|---|---|---|---|---|
| SK hynix | ₩1,691,000 | +12.73% | ₩9.11tn | +₩539.3bn | −₩24.1bn | −₩211.8bn | +₩20.1bn | −₩1.55tn |
| Samsung Electronics | ₩271,000 | +9.49% | ₩6.96tn | +₩1.14tn | +₩159.3bn | −₩86.3bn | −₩23.5bn | −₩1.27tn |
| Samsung Electro-Mechanics | ₩1,396,000 | +0.65% | ₩1.06tn | −₩230.9bn | −₩104.0bn | −₩53.5bn | −₩49.8bn | +₩327.8bn |
| SK Square | ₩1,123,000 | +11.85% | ₩927.6bn | +₩77.1bn | −₩18.7bn | −₩8.5bn | +₩3.6bn | −₩56.5bn |
| Samsung Electronics (Pref.) | ₩191,200 | +10.07% | ₩674.3bn | +₩49.3bn | +₩71.3bn | +₩16.1bn | +₩11.5bn | −₩121.7bn |
| SK eternix | ₩56,000 | −3.11% | ₩394.2bn | −₩13.8bn | −₩16.9bn | −₩7.0bn | +₩2.5bn | +₩32.1bn |
| Kumho E&C | ₩15,650 | +24.21% | ₩390.5bn | +₩6.5bn | +₩0.9bn | +₩0.3bn | +₩0.1bn | −₩6.2bn |
| Hanwha Aerospace | ₩1,167,000 | −0.85% | ₩295.9bn | +₩16.4bn | +₩7.1bn | +₩13.0bn | −₩4.3bn | −₩22.4bn |
| NAVER | ₩219,500 | +5.53% | ₩210.5bn | +₩41.7bn | +₩16.3bn | −₩0.1bn | +₩14.6bn | −₩57.4bn |
| KB Financial Group | ₩160,000 | −3.85% | ₩206.9bn | −₩13.8bn | −₩43.0bn | −₩23.9bn | −₩11.7bn | +₩56.3bn |
Gainers5· Decliners5 — KOSPI & KOSDAQ
A window on the biggest gainers and decliners, and the reasons behind them
KOSPI movers split sharply — chip and AI names surged while financials, energy, and industrials fell as breadth data for Thursday was not yet collected.
On the KOSPI, the day’s advance list (by turnover ≥₩10bn) was led by Kumho Electric (+29.97%), SK Securities (+29.79%), Kumho Construction (+24.21%), SK hynix (+12.73%), and SK Square (+11.85%); declines clustered in autos, financials, and energy, with DN Automotive off −13.77% and Woori Financial Group down −5.82%.On the KOSDAQ, Ingenia Therapeutics (Reg.S) hit the daily limit at +30.00% and Lemediy rose +15.33%, while April Bio fell −19.20% and Kolon TissueGene dropped −16.41%; market breadth data for today’s session had not yet been collected at the time of this edition.
After-Hours Outlook
A window on what to watch in after-hours trade once the regular session ends
After-hours window opens with semiconductor names holding double-digit gains — program trading turned net buyer in non-arbitrage on KOSPI today.
Program TradingBasket orders executed automatically by algorithm, split into arbitrage (index futures vs. cash) and non-arbitrage (pure basket) legs.A sharp shift in non-arbitrage program flow — as seen today when it turned from −₩3,562.6bn on Wednesday to +₩1,271.9bn — is often cited as a mechanical amplifier of index moves. on KOSPI turned net positive at ₩904.4bn today (non-arbitrage +₩1,271.9bn, arbitrage −₩367.5bn), a reversal from Wednesday’s net sell of −₩3,562.6bn; in the current 2026 regime (n=117 short-selling surge events), the five-day forward average return after a surge day has been −0.22% with a 50% down-probability, suggesting no directional edge from that signal alone.NXT’s prior-day after-market session (August 19) recorded ₩1,123.00bn — the largest after-market figure in the five days shown — so today’s extended session activity will be worth monitoring; confirmed NXT data for today will appear in the evening edition after 18:00 KST.