verdict at the close
KOSPI +1.20% to 6,934.91 — KOSDAQ drops 4.48% to 803.23
The KOSPI closed Friday, August 21 (2026) at 6,934.91, up 1.20%, as Samsung Electronics (+3.87%) and SK hynix (+2.31%) anchored a gain that institutions extended into the close.The KOSDAQ finished at 803.23, down 4.48%, with retail investors providing the sole net-buying support of ₩623.7bn against a broad sell-off in biotech, defense, and power-equipment names.
The day’s path
A window marking the hours when direction turned during the session
KOSPI low at 09:01, high at 14:19 — a five-hour, 211.68-point climb that faded modestly into the close at 6,934.91.
Top by trading value10— snapshot
A window on how the top trading-value names have moved up to this hour
Samsung Electronics and SK hynix each printed intraday ranges above ₩100,000 per share as the KOSPI reached its session high of 6,954.12 at 14:19.
| Stock | Prior close | Open | Gap | High (time) | Close | Change | Low (time) |
|---|---|---|---|---|---|---|---|
| Samsung Electronics | 271,000 | 267,000 | −1.48% | 285,000 (14:19) | 281,500 | +3.87% | 266,000 (09:00) |
| SK hynix | 1,691,000 | 1,675,000 | −0.95% | 1,773,000 (09:52) | 1,730,000 | +2.31% | 1,669,000 (09:00) |
| Samsung Electronics (Pref.) | 191,200 | 190,100 | −0.58% | 210,000 (14:21) | 207,000 | +8.26% | 188,600 (09:00) |
| Samsung Electro-Mechanics | 1,396,000 | 1,345,000 | −3.65% | 1,348,000 (09:00) | 1,316,000 | −5.73% | 1,306,000 (10:10) |
| SK Square | 1,123,000 | 1,096,000 | −2.40% | 1,141,000 (09:48) | 1,123,000 | +0.00% | 1,078,000 (09:00) |
| Kumho E&C | 15,650 | 15,650 | +0.00% | 18,200 (09:25) | 14,750 | −5.75% | 14,600 (15:07) |
| Kakao | 38,700 | 38,150 | −1.42% | 38,750 (09:00) | 35,800 | −7.49% | 33,600 (10:52) |
| Samsung Life Insurance | 296,989 | 291,500 | −1.85% | 329,000 (15:10) | 328,500 | +10.61% | 287,000 (09:00) |
| SK Securities | 2,810 | 2,920 | +3.91% | 3,555 (09:05) | 2,955 | +5.16% | 2,820 (14:26) |
| Kumho Electric | 7,460 | 8,000 | +7.24% | 9,690 (09:24) | 8,380 | +12.33% | 7,810 (09:00) |
The KOSPI touched its session low of 6,742.44 at 09:01 before rallying steadily through the morning; Samsung Electronics moved from a low of ₩266,000 at the open to a high of ₩285,000 at 14:19, mirroring the index’s afternoon push.SK hynix peaked earlier at ₩1,773,000 (09:52) and settled back to ₩1,730,000 by close, while Samsung Life Insurance sustained its climb to ₩329,000 at 15:10 — the only top-ten name to make its high in the final hour.
Flow summary
A window on how much foreign investors, retail investors, investment firms and pension funds each bought and sold
Institutions net-bought ₩248.5bn on KOSPI while retail investors sold ₩1.17tn, as foreigners turned net sellers of ₩176bn on the day — a split session that left the KOSPI up 1.20% while the KOSDAQ fell 4.48%.
The stocks that moved the market — top by turnover10
A window on which investor groups backed the most heavily traded stocks
Samsung Electronics and SK hynix together accounted for ₩15.10tn in KOSPI turnover — dominating the top-ten list on a day the index closed at 6,934.91.
Samsung Electronics (₩7,682.4bn turnover, +3.87%) and SK hynix (₩7,415.2bn, +2.31%) together drew the bulk of KOSPI flow, with Samsung Electronics preferred shares (₩2,114.4bn, +8.26%) adding a third chip-group name to the top-three slots.On KOSDAQ, Ingenia Therapeutics (Reg.S) topped turnover at ₩411.8bn despite falling −13.97%, followed by Gido Industries (₩211.6bn, −34.58%) — both heavily traded decliners signaling concentrated selling pressure in the second board.
| Stock | Close | Change | Turnover | Foreign investors | Institutions | Investment firms | Pension funds | Retail investors |
|---|---|---|---|---|---|---|---|---|
| Samsung Electronics | ₩281,500 (≈$203.29) | +3.87% | ₩7.70tn | +₩439.4bn | +₩368.1bn | +₩243.7bn | +₩57.8bn | −₩743.3bn |
| SK hynix | ₩1,730,000 (≈$1,249.37) | +2.31% | ₩7.43tn | +₩14.4bn | +₩111.5bn | −₩12.2bn | +₩70.3bn | −₩1.26tn |
| Samsung Electronics (Pref.) | ₩207,000 (≈$149.49) | +8.26% | ₩2.17tn | −₩97.4bn | +₩181.0bn | +₩112.7bn | −₩7.8bn | −₩93.6bn |
| Samsung Electro-Mechanics | ₩1,316,000 (≈$950.39) | −5.73% | ₩928.8bn | −₩119.5bn | −₩117.0bn | −₩65.4bn | −₩31.5bn | +₩236.4bn |
| SK Square | ₩1,123,000 (≈$811.01) | +0.00% | ₩673.2bn | +₩2.9bn | +₩28.5bn | +₩4.7bn | +₩32.2bn | −₩29.4bn |
| Kumho E&C | ₩14,750 (≈$10.65) | −5.75% | ₩517.4bn | −₩9.9bn | +₩0.8bn | −₩0.2bn | +₩0.1bn | +₩7.6bn |
| Kakao | ₩35,800 (≈$25.85) | −7.49% | ₩353.4bn | −₩52.3bn | −₩45.3bn | −₩15.7bn | −₩5.7bn | +₩96.5bn |
| Samsung Life Insurance | ₩328,500 (≈$237.24) | +10.61% | ₩327.8bn | — | — | — | — | — |
| SK Securities | ₩2,955 (≈$2.13) | +5.16% | ₩273.3bn | — | — | — | — | — |
| Kumho Electric | ₩8,380 (≈$6.05) | +12.33% | ₩246.4bn | — | — | — | — | — |
Gainers5· Decliners5 — KOSPI & KOSDAQ
A window on the biggest gainers and decliners, and the reasons behind them
Financial stocks and Samsung-group names led KOSPI gainers while defense, construction, and power-equipment names dominated the decliners on Friday, August 21 (2026).
Among KOSPI names with turnover above ₩100bn, gainers included Samsung Life Insurance (+10.61%), Samsung Electronics preferred (+8.26%), SK Telecom (+5.80%), Samsung C&T (+5.75%), and Samsung Fire & Marine (+6.27%); decliners included LIG Defence & Aerospace (−11.69%), Korea Circuit (−11.36%), Isoo Chemical (−10.27%), Hanwha Solutions (−8.95%), and Doosan Fuel Cell (−8.98%).On KOSDAQ, Comico surged +27.06% and Gido Industries plunged −34.58%, the sharpest single-stock moves in the session; Alteogen fell −5.74% and Jusung Engineering −4.91% among semiconductor-adjacent names.
After-Hours Outlook
A window on what to watch in after-hours trade once the regular session ends
KOSPI closes up 1.20% but non-arbitrage program selling of ₩837.8bn into the close signals caution heading into after-hours.
Program trading on KOSPI showed total net selling of ₩772.1bn today (non-arbitrage: −₩837.8bn, arbitrage: +₩65.7bn), a reversal from Wednesday Aug 20’s net buying of ₩904.4bn — a divergence between program flows and foreign-investor positioning that the 2026-regime lag data identifies as a signal worth watching.In the current 2026 regime (n=32), days with a semiconductor-to-defensive rotation pattern have been followed by a KOSPI average gain of 2.05% over three sessions with an up-probability of 69%; however, Friday’s foreign futures net-buying of 4,103 contracts contrasts with cash-market net selling of ₩176.0bn, adding an unresolved cross-signal that the data does not resolve on its own.