verdict at the close
KOSPI Drops 5.85% to 6,467.77 as Chip Selloff Deepens
The KOSPI closed at 6,467.77 on Wednesday, August 19 (2026), down 5.85% on the day, swinging across a 213.58-point intraday range between a low of 6,400.81 and a high of 6,614.39.The KOSDAQ ended at 824.49, down 1.16%, outperforming its large-cap counterpart as the session’s heaviest selling was concentrated in semiconductor heavyweights rather than the smaller-cap board.
The day’s path
A window marking the hours when direction turned during the session
KOSPI opened lower at 6,528.77, recovered to a high of 6,614.39 by 10:22, then sold off steadily to close at 6,467.77, down 5.85%.
Top by trading value10— snapshot
A window on how the top trading-value names have moved up to this hour
Chips drove both turnover and losses on August 19 (2026) as SK hynix and Samsung Electronics hit session lows in the final hour before a partial close-end recovery.
| Stock | Prior close | Open | Gap | High (time) | Close | Change | Low (time) |
|---|---|---|---|---|---|---|---|
| SK hynix | 1,662,000 | 1,545,000 | −7.04% | 1,559,000 (10:20) | 1,500,000 | −9.75% | 1,486,000 (15:09) |
| Samsung Electronics | 268,500 | 251,500 | −6.33% | 254,500 (10:15) | 247,500 | −7.82% | 246,500 (15:13) |
| Samsung Electro-Mechanics | 1,440,000 | 1,357,000 | −5.76% | 1,431,000 (10:20) | 1,387,000 | −3.68% | 1,350,000 (09:00) |
| SK Square | 1,135,000 | 1,030,000 | −9.25% | 1,042,000 (10:22) | 1,004,000 | −11.54% | 993,000 (09:26) |
| Samsung Electronics (Pref.) | 188,300 | 176,400 | −6.32% | 178,700 (10:23) | 173,700 | −7.75% | 172,700 (09:05) |
| Hanwha Aerospace | 1,146,000 | 1,255,000 | +9.51% | 1,255,000 (09:02) | 1,177,000 | +2.71% | 1,150,000 (09:45) |
| SK eternix | 58,500 | 56,400 | −3.59% | 60,700 (09:10) | 57,800 | −1.20% | 55,000 (09:16) |
| Hyundai Motor | 435,000 | 416,000 | −4.37% | 422,500 (10:30) | 414,000 | −4.83% | 406,500 (09:27) |
| Samsung SDI | 488,000 | 467,500 | −4.20% | 501,000 (10:21) | 487,000 | −0.20% | 466,000 (09:00) |
| LG Electronics | 208,011 | 198,400 | −4.62% | 210,500 (10:07) | 201,500 | −3.13% | 197,300 (09:00) |
The KOSPI touched its session low of 6,400.81 at 09:17 and its high of 6,614.39 at 10:22, after which the index drifted progressively lower through the afternoon; SK hynix reached its intraday low of ₩1,486,000 at 15:09 before the simultaneous-quote close.On NextTrade (NXT) — Korea’s Alternative ExchangeA licensed alternative trading system that operates alongside the KRX (Korea Exchange), allowing extended-hours trading in pre-market, main, and after-market sessions.NXT data provides a real-time breadth snapshot during the KRX session and is the main venue for extended-hours price discovery for Korean equities. (the alternative exchange, 20-minute delayed snapshot as of 15:25 KST), 490 names declined against 103 advances among 608 listed securities, with combined NXT turnover of ₩11,394.1bn; these are NXT-only figures and are not confirmed final.
Flow summary
A window on how much foreign investors, retail investors, investment firms and pension funds each bought and sold
Foreigners and institutions jointly sold ₩3.49tn on KOSPI as the index closed at 6,467.77, down 5.85%, on Wednesday, August 19 (2026).
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 accounted for ₩12.04tn in KOSPI turnover, with both names down 9.75% and 7.82% respectively.
Of the ten most-traded KOSPI names by turnover on Wednesday, August 19 (2026), nine closed lower, with SK hynix (₩6,382.8bn) and Samsung Electronics (₩5,657.1bn) accounting for the bulk of the session’s volume at a combined ₩12,039.9bn.Hanwha Aerospace was the sole gainer among the top ten, adding 2.71% on ₩486.8bn in turnover; Samsung Electro-Mechanics led the mid-tier decliners at –3.68% on ₩1,021.8bn.
| Stock | Close | Change | Turnover | Foreign investors | Institutions | Investment firms | Pension funds | Retail investors |
|---|---|---|---|---|---|---|---|---|
| SK hynix | ₩1,500,000 | −9.75% | ₩6.38tn | −₩1.83tn | −₩471.9bn | −₩567.8bn | +₩28.7bn | +₩2.22tn |
| Samsung Electronics | ₩247,500 | −7.82% | ₩5.66tn | −₩1.04tn | −₩733.5bn | −₩665.1bn | +₩3.3bn | +₩1.69tn |
| Samsung Electro-Mechanics | ₩1,387,000 | −3.68% | ₩1.02tn | −₩149.9bn | +₩1.2bn | +₩18.4bn | −₩4.5bn | +₩140.5bn |
| SK Square | ₩1,004,000 | −11.54% | ₩633.4bn | −₩216.5bn | −₩23.3bn | −₩2.1bn | −₩6.4bn | +₩233.4bn |
| Samsung Electronics (Pref.) | ₩173,700 | −7.75% | ₩518.5bn | −₩133.8bn | −₩41.6bn | +₩2.9bn | −₩9.8bn | +₩166.3bn |
| Hanwha Aerospace | ₩1,177,000 | +2.71% | ₩486.8bn | −₩92.8bn | +₩55.4bn | −₩1.3bn | +₩43.7bn | +₩36.8bn |
| SK eternix | ₩57,800 | −1.20% | ₩226.9bn | −₩4.3bn | +₩13.5bn | +₩5.6bn | +₩0.0bn | −₩8.6bn |
| Hyundai Motor | ₩414,000 | −4.83% | ₩220.1bn | −₩22.6bn | −₩23.1bn | −₩11.7bn | −₩3.5bn | +₩44.5bn |
| Samsung SDI | ₩487,000 | −0.20% | ₩192.5bn | +₩8.0bn | −₩4.7bn | −₩1.9bn | −₩7.1bn | −₩3.1bn |
| LG Electronics | ₩201,500 | −3.13% | ₩174.1bn | +₩2.3bn | −₩15.6bn | −₩8.6bn | +₩6.4bn | +₩12.7bn |
Gainers5· Decliners5 — KOSPI & KOSDAQ
A window on the biggest gainers and decliners, and the reasons behind them
Semiconductors led declines on both boards while construction and defense names posted the session’s notable gains against an otherwise broadly lower market.
Among KOSPI names with turnover above ₩100bn, the heaviest decliners included SK Square (–11.54%), Samsung Life Insurance (–11.11%), SK hynix (–9.75%), and Samsung Electronics (–7.82%), clustering the session’s losses heavily in financials and technology.Gainers on volume were fewer and smaller: Jobee (+17.74%), Busan Industry (+14.29%), Doosan Fuel Cell (+9.94%), and Hyundai E&C (+5.81%) were among the standout advances. On KOSDAQ, Ingenia Therapeutics (Reg.S) fell 21.62% on ₩535.6bn in turnover, while Bioneer (+29.99%), HanChem (+29.94%), and Hwashin Jeonggong (+29.79%) led the upside.
After-Hours Outlook
A window on what to watch in after-hours trade once the regular session ends
Broad selling and a provisional crash-signal score of 3 leave the after-market watch focused on semiconductor names and futures positioning.
The crash-precursor score stood at 3 at the close (signals triggered: Advance-Decline Ratio (ADR)The ratio of the number of rising stocks to the number of falling stocks in a given market on a given day.An ADR well below 1.0 signals that weakness is broad rather than concentrated in a few large-caps, making the decline harder to attribute to any single stock or sector. and short-surge surge), with the volatility reading at the 93rd percentile on an expanding-window basis in the current 2026 regime; in the 2026 regime, short-surge events of this type have been followed by a KOSPI return averaging –0.43% over five days in 114 observations, with a downside probability of 51%.Foreign investors net sold –4,361 KOSPI futures contracts today (provisional), reversing Monday’s net buy of +808 contracts; in the 2026 regime across 152 sample days, foreign futures net selling on the same day as large foreign spot selling has shown a same-day correlation of 0.515 with the KOSPI, while the one-day-lag correlation is 0.162 — directional persistence is present but not guaranteed.