Two Giants Barely Budged. The Forest Grew Taller.

DAILY MARKET NOTE / 19 OCT 2026

Opened Down 3%.
Closed at the Day’s High.

KOSPI +1.76% to close at 5,768.01, rising for a second session. The opening move of -3.17% marked the day’s low, while the close was the high. The KOSDAQ was +1.78%, finishing above 800.Friday’s U.S. selloff in AI and chip stocks carried into Monday’s opening prices. The Philadelphia Semiconductor Index posted a -3.83% return, its eighth consecutive decline.The strongest gains came from batteries and biotech. Samsung SDI (+11.70%) rallied after reports that Chinese ESS suppliers were exiting the U.S. Samsung Biologics (+9.94%) rose after a court extended strike-related protections to more production processes. SK Hynix (+0.39%) lagged.In KRX trading, institutions bought a net ₩575bn and other corporations ₩549.4bn, while individuals sold ₩1.086tn. Foreign investors sold a modest ₩38bn as of the 3:38 p.m. snapshot; figures including Nextrade, however, showed net foreign buying.

The U.S. chip selloff was priced in at the open, but the KOSPI never revisited that low and finished at its intraday high. Nearly three in four KOSPI stocks advanced, with large-cap battery and biotech names leading the gains.

MARKET PATH / 01

-3.17% at the Open, +1.76% at the Close—and the Day’s High

When did the market turn, and where did it finish?

The KOSPI opened at 5,488.41, down 3.17%, and that opening print remained the session low. It turned positive shortly after 10:10 a.m., slipped back toward 5,630 around 10:50, and recovered again around 11:40. The index reached 5,700 around 12:10 p.m., briefly retreated toward 5,680 around 2:20, then accelerated after 3 p.m. to close at 5,768.01—the day’s high. That was a 279.60-point, or 5.09%, rise from open to close.

KOSPI · 09:00~15:30Open 5,488.41 (day’s low) → Positive around 10:10 a.m. → Back near 5,630 around 10:50 → Gains accelerate after 3 p.m. → Close at the high

OPEN5,488.41-3.17%

HIGH5,768.01+1.76%

LOW5,488.41-3.17%

CLOSE5,768.01+1.76%

THE READ

Selling pressure was concentrated at the opening bell; the market never retested that price. The U.S. rout set the opening level, but not the direction of the rest of the session (interpretation).The recovery was not a straight line. After briefly turning positive in the morning, the index slipped back into negative territory. It did not establish itself above Friday’s close until around 11:40 a.m. The high-of-day finish came from a final half-hour acceleration.The KOSDAQ followed a similar pattern: its open was the session low and it closed just 0.03 point below the high. Gains extended beyond a handful of large caps; advancing stocks outnumbered decliners in both markets.

OPEN · MORNING

-3.17%The open and the first turn positive, around 10:10 a.m.

The KOSPI opened at 5,488.41, its session low. It approached 5,590 around 9:05 a.m., pulled back toward 5,560 around 9:25, and then gained momentum after 10.It crossed Friday’s close of 5,668.05 shortly after 10:10 a.m. and came within reach of 5,700 around 10:20.

MIDDAY

Back below zero around 10:50 a.m.; positive again by 11:40

The index faded from about 10:25 a.m. and approached 5,630 around 10:50. It traded in the 5,640–5,660 area until approximately 11:30.It regained positive territory around 11:40 a.m., reached about 5,700 by 12:10 p.m. and traded near 5,710–5,720 around 1 p.m. (5,717.19 at 1 p.m., as reported).

AFTERNOON

Another dip around 2:20 p.m., then a stronger finish

The index hovered around 5,700–5,720 from roughly 1:10 to 2:10 p.m., dipped toward 5,680 around 2:20, and gained pace after 3 p.m. before closing at the session high.The KOSDAQ opened at 773.06 (-2.73%), which was also its low; its high was 808.92 and it closed at 808.89. KOSPI turnover was ₩17.2174tn, 86% of the prior session’s level and 0.75 times the preceding five-session average.

The line traces the KOSPI’s five-minute chart, with horizontal positions representing actual times. The opening, high, low and closing prices—and the reported 1 p.m. level—are confirmed figures; other points are rounded to broad price ranges. The dashed line marks Friday’s 5,668.05 close.

WHY / 02

U.S. Chips Set the Opening; Batteries and Biotech Drove the Rebound

What drove the opening decline—and what brought buyers back

THE SHORT VERSIONFriday’s sharp U.S. selloff in AI and chip stocks carried through the weekend, putting the KOSPI down more than 3% at Monday’s open. The reasons for the subsequent rally came largely from outside semiconductors. Korean battery stocks surged after a Taiwanese report said major Chinese energy storage system (ESS) suppliers had effectively exited the U.S. market. Samsung Biologics also jumped after a court expanded the operations protected from industrial action. Japanese stocks, by contrast, ended the same day lower.

Friday in the U.S.: AI financing worries meet an oil shock

U.S. stocks — Friday, Oct. 16: Nasdaq -2.14% (its steepest drop since July 23); S&P 500 -1.09%; Dow -0.34%. Reports cited concerns over the returns and debt burden of AI infrastructure investment, compounded by a jump in oil prices.Semiconductors — The Index: -3.83% (11,137.29). Its eighth consecutive loss was reportedly the longest losing streak since 2008. AI data-center company CoreWeave: -11.91%Oil — Brent crude rose to $109.86 (+3.72%), its highest since May. Reports pointed to geopolitical risks as a driver.Korea’s opening — Because the U.S. selloff came after Korea’s Friday close, Monday, Oct. 19 was the first chance for Korean prices to reflect it. The KOSPI still opened sharply lower despite gains in U.S. stock-index futures before the bell (Nasdaq 100 futures +0.69% at 8:15 a.m. KST, according to reports).A counterpoint — Oil prices eased during Monday’s Asian session. Reports suggested that a partial U.S. suspension of sanctions on Russia could allow more supply. It is difficult to isolate how much, if at all, this helped Korea’s intraday recovery.

-3.83%Philadelphia Semiconductor Index, Oct. 16 U.S. close

SHOW SOURCES & DETAILS

U.S. weekly performance — Nasdaq −4.48%, its worst week since June; S&P 500 −1.95%. Both indexes fell below their 50-day moving averages (Financial News). The VIX closed at 19.99, up 21.45%, after briefly moving above 22 intraday for the first time in four months.

Chip and AI shares — Micron −5.63%; Broadcom −4.52%; Nebius −12.18%; Meta −3.72%; Nvidia −1.43% ($214.13). Reports gave different declines for SK Hynix’s U.S. : −5.68% or −6.58%, depending on the source.

Oil — WTI closed at $101.41 (+3.51%), its highest since Sept. 17 (U.S. session, Oct. 16). In Asian trading on Oct. 19, Brent eased toward $108 and WTI briefly fell below $100, according to reports. News of the sanctions suspension was tied to an Oct. 16 U.S. executive order.

U.S. equity futures — Nasdaq 100 futures were up 0.69% at 8:15 a.m. KST (Jaekyung Ilbo); an article published at 12:20 p.m. reported an advance of about 1% (EconomyBlock).

Beyond Chips: Reports of Chinese ESS Exits and a Samsung Biologics Court Ruling

Batteries — Taiwanese technology outlet DigiTimes reported, citing a U.S. supply-chain source on Oct. 19, that nearly all major Chinese ESS suppliers that once dominated the American market had withdrawn from U.S. operations this year amid tighter regulation, tariffs and ownership reviews. Samsung SDI (+11.70%) and LG Energy Solution (+7.20%) were among the day’s biggest winners. What is confirmed — This was an exclusive report from a single outlet, and the publicly available text did not name the companies or define the scope of their exit. The potential benefit for Korean suppliers remains an expectation, not a demonstrated result (interpretation). Hopes for AI data-center ESS demand in the U.S. and bargain buying after recent declines were also in play; the report alone cannot explain the full rally.Samsung Biologics — An appellate panel sitting in Incheon expanded the number of production processes protected against union work stoppages from three to nine (reported on the evening of Oct. 16). The ruling did not ban a strike outright; it barred interference with normal operations in designated critical processes. The union reportedly canceled an Oct. 21 rally and said its planned Oct. 26 strike could change. Samsung Biologics shares (+9.94%) posted the largest gain among the KOSPI’s ten biggest companies by market capitalization.Dip buying — Lee Kyung-min of Daishin Securities cited bargain hunting after the recent slump and a moderation in foreign net selling. He characterized the rally as led by sectors other than AI semiconductors.Across Asia — Japan’s Nikkei 225 ended -0.62%, weighed down by chip stocks (NewsPim). Korean stocks followed a different path as battery and biotech catalysts combined with broad-based dip buying (interpretation). Because the markets have different sector weights, the divergence alone does not establish its cause.

+11.70%Samsung SDI on the day of the report of Chinese ESS exits

SHOW SOURCES & DETAILS

DigiTimes’ headline — “Exclusive: Chinese energy storage giants reportedly exit US as two-way tech restrictions open door for non-Chinese suppliers.” Published at 9:35 a.m. Taiwan time on Oct. 19; quoted by Korean media including MoneyToday at 11:20 a.m.

Brokerage commentary — Jang Jung-hoon of Samsung Securities said investors might return their attention to U.S. policies aimed at reducing reliance on Chinese ESS suppliers after third-quarter earnings season. Kim Seok-hwan of Mirae Asset Securities expected North American ESS installations to rise further in Q3 after reaching a record in Q2 (MoneyToday).

Samsung Biologics ruling — An April lower-court order protected three processes; the appellate panel added six upstream processes, including cell culture and purification. Violations carry a payment of ₩20m per incident. The union maintained its broader plans for collective action (Hankook Ilbo). The decision was cited as a driver of the shares’ early gains (Korea Economic Daily, 9:59 a.m.).

KOSDAQ battery names — EcoPro +11.19%; EcoPro BM +8.33% (NewsPim).

Nikkei 225: 64,916.70 (−0.62%). The index briefly dipped below 64,000 before paring losses. The TOPIX rose 0.04% (NewsPim).

Chinese economic data released intraday — China’s Q3 GDP rose 4.5% year over year, against a Reuters consensus of 4.4%; September industrial production rose 5.5%, retail sales 1.1%, and January–September fixed-asset investment fell 7.2% (MoneyToday). The release preceded the KOSPI’s renewed climb around 11:40 a.m., but its contribution to that move cannot be established.

MONEY / 03

Institutions and Corporations Bought;
Foreign Flows Depend on Which Market You Count

Who was behind today’s advance

On the Korea Exchange (KRX), institutions and other corporations were net buyers while retail investors sold. Foreign investors were modest net sellers of ₩38bn in the 3:38 p.m. snapshot. But adding transactions on flips foreign flows to net buying of ₩624.3bn. The difference is which trading venues the totals cover. As in previous editions, this report uses KRX-only figures unless stated otherwise. Institutional buying concentrated in large-cap battery and biotech companies; both institutions and foreign investors sold more SK Hynix than any other stock.

INSTITUTIONS · KOSPI CASH EQUITIES · KRX SNAPSHOT, 3:38 P.M.

+₩575bn

Institutions were net sellers on Oct. 16 (−₩683bn) but switched to buying today. An article at 10:13 a.m. already showed ₩383bn in net purchases, including at +₩220bn and securities firms at +₩169bn (Opinion News). An article at 1 p.m. put total institutional purchases at ₩461.5bn (Aju Business Daily).By stock — Institutions’ largest net purchases were LG Energy Solution (+₩132bn), Samsung SDI (+₩115.7bn) and Samsung Biologics (+₩97.3bn). Their largest net sales were SK Hynix (−₩242.2bn), Samsung Electro-Mechanics (−₩75.4bn) and SK Square (−₩72.4bn), based on our 3:51 p.m. regular-session data.Foreign investors — −₩38bn net. Their top net buys were Samsung Electronics (+₩172bn) and Samsung SDI (+₩110.7bn); the biggest net sale was SK Hynix (−₩217.6bn). They also sold LG Energy Solution (−₩59.6bn) and Samsung Biologics (−₩21.6bn), moving in the opposite direction from institutions in those two names (our 3:51 p.m. data). · +₩549.4bn (preliminary KRX figure; MoneyToday), almost as much as institutions. This category includes corporate share buybacks, but without company-level repurchase figures it would be wrong to attribute the full amount to buybacks.Retail investors — −₩1.086tn net, a larger outflow than the −₩485bn recorded on Oct. 16.Including Nextrade — Foreign investors +₩624.3bn; institutions +₩880.9bn; other corporations +₩427.6bn; retail investors −₩1.9312tn (MoneyToday). Because Nextrade continues trading after the KRX regular session, the eventual daily totals may change again.FX — The dollar traded at ₩1,330.3 as of 3:30 p.m., down from ₩1,331.4 at the same time on Oct. 16, a ₩1.1 appreciation in the won. It was the strongest won against the dollar at that regular-session reference point since Oct. 2, 2024 (NewsPim). The currency strengthened even as foreigners were small net sellers of KRX cash equities: the two flows did not point in the same direction.Futures and program trading — Foreign investors sold a net ₩93bn in futures, versus ₩954bn on Oct. 16; institutions bought ₩169bn. In program trades, buying totaled +₩521.7bn, while trades were −₩60.8bn.

KOSPI NET BUYERSInstitutions · Other corporations

KOSPI NET SELLERSRetail · Foreign investors

DETAILED FLOW DATA

Three investor groups — Institutions +₩575bn, foreigners −₩38bn and retail −₩1.086tn; our KRX KOSPI snapshot at 3:38 p.m. (source data in ₩1bn increments). Foreign figures include the “other foreign” category. The three groups net to −₩549bn. Published reports rounded in units of ₩100m show institutions +₩574.7bn, foreigners −₩37.9bn and retail −₩1.0862tn (Blockmedia, 3:47 p.m.).
Cross-check — Summing stock-level flows across all KOSPI and KOSDAQ companies in our 3:51 p.m. collection gives foreigners −₩180.1bn, institutions +₩638.5bn and retail −₩1.0194tn. These nearly match the combined 3:38 p.m. market totals (foreigners −₩183bn, institutions +₩642bn, retail −₩1.022tn).
Two trading scopes — Foreign investors were net sellers in KRX-only figures, but net buyers when Nextrade was included. MoneyToday published both side by side (preliminary KRX-only: foreigners −₩36.4bn, institutions +₩574.6bn, other corporations +₩549.4bn and retail −₩1.0862tn). The figures reported by NewsPim, Asia Business Daily and EToday—foreigners +₩624.7bn, institutions +₩878.8bn and retail −₩1.929tn—were close to the combined-market totals. The discrepancy was visible early in the session: NewsPim reported +₩525.7bn foreign buying in a 10:26 a.m. article, while a 10:13 a.m. KRX-only snapshot showed −₩32.3bn. The principal difference, therefore, is market coverage. One unresolved wrinkle: Nextrade’s after-hours market opens at 3:40 p.m., before the KRX’s 4 p.m. after-hours session; we cannot tell how much after-hours turnover was included in articles published after 3:55 p.m.
Intraday foreign flows — A 10:13 a.m. article reported −₩32.3bn, after foreigners had switched from early net buying to selling (Opinion News). A 1 p.m. article reported −₩134.1bn (Aju Business Daily); the closing snapshot was −₩38bn. These are differences between cumulative readings, not a minute-by-minute record. The articles do not specify whether their publication and measurement times coincide.
Other corporations intraday — A 10:13 a.m. article showed +₩130bn and attributed the activity in part to SK Hynix buybacks (Opinion News). The company’s disclosed repurchase period runs through Nov. 19.
Stock-level detail — Our 3:51 p.m. KRX regular-session data show foreign net buys ranked 3–5: SK Square +₩46.5bn, Samsung Electro-Mechanics +₩35.6bn and Doosan +₩34.7bn. Foreign net sells ranked 2 and 4: Samsung Electronics preferred shares −₩98.6bn and Samyang Foods −₩25.3bn. Institutional net buys ranked 4–5: Samsung Electronics preferred +₩47.1bn and Hyundai Motor +₩41.7bn. Institutional net sells ranked 4–5: Doosan −₩32.2bn and HD Hyundai Heavy Industries −₩18bn. Rankings match KRX-based reports from Pinpoint News at 3:55 and 3:58 p.m.
SK Hynix — Retail investors sold ₩145.1bn net, foreigners ₩217.6bn and institutions ₩242.2bn. All three were net sellers, even as the stock gained 0.39% (our 3:51 p.m. data).

TOTAL PROGRAM TRADING+₩460.9bn

PROGRAM ARBITRAGE−₩60.8bn

KOSPI 200 FUTURES · INSTITUTIONS+₩169bn

KOSPI 200 FUTURES · RETAIL−₩67bn

Program trading at the regular-session close (3:35 p.m.): arbitrage −₩60.8025bn; non-arbitrage +₩521.686bn; combined +₩460.884bn. Futures positions are from the KRX’s 3:49 p.m. reading, provided in ₩1bn increments.
Five-session totals (Oct. 13–19) — KOSPI foreign investors −₩9.014tn; institutions +₩4.083tn; retail +₩1.631tn; foreign investors’ KOSPI 200 futures +₩1.398tn (KRX, source figures in ₩1bn increments).
KOSDAQ — Institutions +₩67bn; retail +₩64bn; foreign investors −₩145bn (our KRX snapshot at 3:38 p.m.).
Short selling — KOSPI-listed shares saw ₩898.7bn in short-sale turnover, down from ₩1.2573tn on Oct. 16. This combines KRX regular-session trades (ending at 3:30 p.m.) with Nextrade main-market trades (ending at 3:20 p.m.). LG Energy Solution ranked first at ₩87.7bn, or 21.3% of that stock’s trading turnover; SK Hynix followed at ₩72.9bn and SK Square at ₩61.4bn.

SECTOR / 04

Where Strength—and Weakness—Showed Up

The distribution of winners and laggards, not just a leaderboard

THE SHORT VERSIONNearly three in four KOSPI stocks rose. Batteries were the clear leaders: every constituent of three related KRX thematic indexes advanced. Biotech and pharmaceuticals followed. Semiconductors barely moved overall, with only five of the 15 stocks in the Semiconductor Top 15 index gaining.

STRONG

SECONDARY BATTERY TOP 10KRX THEMATIC INDEX+8.43%

EV TOP 15KRX THEMATIC INDEX+7.31%

PHARMACEUTICALSKOSPI INDUSTRY INDEX+5.77%

BIOTECH TOP 10KRX THEMATIC INDEX+4.59%

CHEMICALSKOSPI INDUSTRY INDEX+3.56%

WEAK

SAMSUNG ELECTRO-MECHANICSINDIVIDUAL STOCK-1.52%

AI SEMICONDUCTORSKRX THEMATIC INDEX-1.29%

SK SQUAREINDIVIDUAL STOCK-0.51%

SEMICONDUCTOR TOP 15KRX THEMATIC INDEX-0.10%

SK HYNIXINDIVIDUAL STOCK+0.39%

Advancers made up 74.0% of KOSPI stocks—down from 82.9% on Oct. 16, but still nearly three out of four. On the KOSDAQ, the share was 68.5%.Market breadth — KOSPI: 679 advancers (including two limit-up stocks), 205 decliners (including one limit-down) and 33 unchanged. KOSDAQ: 1,188 advancers (including two limit-up), 470 decliners (including one limit-down) and 77 unchanged. Twenty-one of the KOSPI’s 24 industry groups rose.Batteries — Every constituent advanced in all three indexes: Secondary Battery Top 10, K-AISecondary Battery (+9.72%) and EV Top 15. POSCO Future M +10.90% and LG Chem +8.46%. Both produce battery cathode materials and are included in the KOSPI chemicals group, where 91 of 122 stocks rose. On Oct. 16, the Secondary Battery Top 10 had fallen -0.27%Biotech and pharmaceuticals — Samsung Biologics +9.94%. Of 55 traded KOSPI pharmaceutical stocks, 41 rose; nine of the ten Biotech Top 10 members advanced. KOSDAQ pharmaceuticals +1.90%—a smaller gain than their KOSPI counterparts. Alteogen +2.14% · HLB +3.00%Semiconductors — Samsung Electronics +1.16% and SK Hynix +0.39%. Only six of the 20 AI Semiconductor constituents rose. On the KOSDAQ, equipment maker EO Technics -2.34% (Oct. 16: +5.91%); Leeno Industrial -1.98%. The AI Semiconductor index reversed sharply from Oct. 16, when all 20 constituents had advanced.Share of market-cap gains — Samsung Electronics, its preferred shares and SK Hynix account for roughly half of total KOSPI market capitalization, yet together they generated only about one-quarter of the day’s increase in aggregate market value (our estimate). Most of the rest came from large caps outside semiconductors and broad gains across individual stocks.

Industry figures are KOSPI and KOSDAQ industry indexes; thematic figures are KRX theme indexes; stock figures are individual closing-price moves. They are calculated differently and should not be read as a single comparable ranking. SK Hynix appears in the WEAK column despite rising, because it substantially lagged the overall index.

SECTOR DATA & METHODOLOGY

Market-cap gain estimate — The three stocks added approximately ₩21tn in market capitalization (Samsung Electronics ~₩14.6tn, SK Hynix ~₩3.7tn and Samsung Electronics preferred ~₩3.0tn). Dividing this by the estimated ₩82tn rise in aggregate KOSPI market capitalization (the index’s 1.76% gain applied to approximately ₩4,680tn in Oct. 16 market value) gives about 26%. On the same basis, LG Energy Solution (~₩6.8tn), Samsung Biologics (~₩6.0tn) and Hyundai Motor (~₩2.9tn) contributed around 19% combined. These are approximate shares of market-cap growth, not formal index-point contributions, which can differ.
Semiconductors — KRX AI Semiconductor −1.29% (six of 20 constituents gained); Semiconductor Top 15 −0.10% (five of 15 gained); K-AISemiconductor TOP2+ −0.14% (five of ten gained); KOSPI electrical & electronics +1.35% (55 of 84 gained); KOSDAQ electrical & electronics +1.73%; KOSDAQ machinery & equipment +0.72%. Jusung Engineering −0.48%; Wonik IPS −0.46%.
Other notable moves (no single industry-wide catalyst confirmed by reporting) — KOSDAQ financials +7.10% (49 of 103 stocks gained; 18 unchanged); KOSPI metals +4.98% (49 of 62 gained; Korea Zinc +5.60%, Sam-A Aluminium +13.87%); automakers Hyundai Motor +4.49% and Kia +5.26%; KOSPI insurance +2.85% (12 of 13 gained); KOSPI medical & precision equipment −2.83% (three of eight gained).
KOSPI industry indexes — Pharmaceuticals +5.77%; Metals +4.98%; Entertainment & Culture +4.24%; Chemicals +3.56%; Insurance +2.85%; IT Services +2.81%; Transportation Equipment & Parts +2.78%; Machinery & Equipment +2.42% (all 29 stocks up); General Services +2.17%; Transportation & Warehousing +1.97%; Manufacturing +1.84%; Securities +1.83%; Electricity & Gas +1.58%; Electrical & Electronics +1.35%; Financials +1.26%; Nonmetals +1.22%; Distribution +1.22%; Food, Beverages & Tobacco +1.20%; Construction +1.13%; Real Estate +0.71%; Telecommunications +0.60%; Paper & Wood −0.05%; Textiles & Apparel −0.84%; Medical & Precision Equipment −2.83%.
KOSDAQ industry indexes — Financials +7.10%; Metals +4.03%; Paper & Wood +3.12%; Transportation Equipment & Parts +3.02%; Entertainment & Culture +2.44%; General Services +2.32%; Chemicals +1.97%; Pharmaceuticals +1.90%; Electrical & Electronics +1.73%; IT Services +1.66%; Publishing & Media Reproduction +1.56% (two stocks); Manufacturing +1.47%; Other Manufacturing +1.09%; Food, Beverages & Tobacco +1.02%; Textiles & Apparel +0.96%; Machinery & Equipment +0.72%; Medical & Precision Equipment +0.67%; Construction +0.48%; Transportation & Warehousing +0.31%; Distribution +0.01%; Telecommunications −0.10%; Nonmetals −1.28%.
KRX thematic indexes — K-AISecondary Battery +9.72% (all ten constituents up); Secondary Battery Top 10 +8.43% (all ten up); EV Top 15 +7.31% (all 15 up); Climate Change Solutions +4.80%; Biotech Top 10 +4.59%; BBIG +4.52%; KOSDAQ Top 10 +4.09%; K-AIDefense TOP5+ +3.99% (all ten constituents up); Licensing Biotech +3.86%; AI Power Infrastructure +3.25%; KOSPI Preferred Shares +2.34%; Shipbuilding Top 10 −0.05%; Semiconductor Top 15 −0.10%; K-AISemiconductor TOP2+ −0.14%; AI Semiconductor −1.29%.
Ten largest KOSPI companies by market value — Samsung Electronics +1.16% (₩218,000); SK Hynix +0.39% (₩1,277,000); Samsung Electronics preferred +2.21%; SK Square −0.51%; LG Energy Solution +7.20% (₩432,000); Samsung Electro-Mechanics −1.52%; Hyundai Motor +4.49%; Samsung Biologics +9.94% (₩1,427,000); KB Financial Group +1.69%; Samsung Life Insurance +2.52%.
Counts of advancing and declining stocks — KOSPI: two limit-up, 677 other advancers, 33 unchanged, 204 other decliners and one limit-down. KOSDAQ: two limit-up, 1,186 other advancers, 77 unchanged, 469 other decliners and one limit-down.
Breadth calculations — KOSPI 74.0% (679/917); KOSDAQ 68.5% (1,188/1,735). The numerator includes ordinary advancers and limit-up stocks. The denominator includes limit-up, up, unchanged, down and limit-down stocks.
KOSDAQ trading turnover — ₩4.647tn, or 0.74 times the preceding five-session average.
Constituent counts refer to stocks traded that day. Industry-index returns are market-cap-weighted price changes, not the net cash entering each industry.

CHANGE / 05

Friday’s Questions, Monday’s Answers

Checking the conditions set at the previous close

YESTERDAY → TODAY

01 The Philadelphia Semiconductor Index fell again, marking eight straight declines. 02 Foreign investors remained net sellers of KRX cash equities (−₩38bn at 3:38 p.m.), so the prior day’s buying did not continue, although combined KRX-plus-Nextrade figures showed net buying. 03 The KOSPI opened 101.92 points below its Oct. 16 low of 5,590.33, yet finished higher for a second day.None of the three checks gave a clear signal for today’s rebound, yet the KOSPI closed higher for a second session. In KRX-only flows, institutional and corporate purchases supported the market as battery and biotech shares rose (interpretation).

Philadelphia Semiconductor Index — Did it close higher?

-0.88%

→

-3.83%

Foreign KOSPI cash flows (KRX) — Did net buying continue?

+₩341bn

→

−₩38bn

KOSPI intraday low — Did 5,590.33 hold?

5,590.33

→

5,488.41

Check 01: The Philadelphia Semiconductor Index went from −0.88% (11,581.22) on Oct. 15 to −3.83% (11,137.29) on Oct. 16. It neither closed higher nor recovered the Oct. 14 closing level of 11,684.38. Check 02 uses our KRX 3:38 p.m. snapshot. For check 03, Monday’s low was below Friday’s. The index finished higher, but that is not the same as meeting the second-stage condition, which required the previous low to hold.

NEXT / 06

What to Watch in the Next Session

Three tests tonight and in Tuesday’s Korean market

Can U.S. semiconductors end an eight-session losing streak?

Check the Philadelphia Semiconductor Index at the U.S. close on Oct. 19. Stage 1: finish higher. Stage 2: finish higher and recover at least half the 443.93 points lost on Oct. 16—meaning a close of 11,359.26 or above (+1.99%).

Can the battery rally last beyond one session?

The KRX Secondary Battery Top 10 closed today at 3,912.12 (+8.43%). Stage 1: finish above that level on Oct. 20. Stage 2: meet Stage 1 with at least six of the index’s ten constituents advancing.

Will institutions buy for a second straight day?

Institutions bought a net ₩575bn today (3:38 p.m. snapshot). Stage 1: record net buying again on Oct. 20. Stage 2: meet Stage 1 with foreign investors also net buyers. Use the KRX-only 3:38 p.m. snapshot for comparison.

COMING UP

U.S. LOCAL10/20~22 — Nvidia GTC Berlin (Jensen Huang keynote on the 21st); U.S. local Oct. 21 — Meta, IBM, Lam Research and Texas Instruments report earnings; Tesla reports after the close; Oct. 21 — Korean Customs Service trade figures for Oct. 1–20 (expected release); Oct. 22 — Bank of Korea Monetary Policy Board meeting; U.S. local Oct. 22 — Western Digital earnings; U.S. local Oct. 23 — preliminary U.S. October PMI readings; Oct. 26 — planned Samsung Biologics union strike date (subject to change, according to reports); 10/27~28 — Federal Reserve meeting; SK Hynix’s disclosed share-repurchase window runs through Nov. 19.

The market recovered its entire opening loss, but the semiconductor giants contributed relatively little to the advance. On the KRX, institutions and other corporations were the principal net buyers. The next answers come from whether U.S. chips break their losing streak tonight—and whether battery shares hold today’s gains on Oct. 20.

SOURCES & DATA NOTES

Reference date: Oct. 19, 2026. Closing prices for indexes, industries and individual shares use Korea Exchange regular-session data.09:00~15:30DATA SCOPE
Overseas news and economic figures — Only information published before 8 p.m. KST on Oct. 19 is included.
Domestic investor flows — Collected from the KRX regular session (investor-group totals at 3:38 p.m.; stock-level figures at 3:51 p.m.); after-hours trades excluded.
Indexes — KOSPI open 5,488.41, high 5,768.01, low 5,488.41, close 5,768.01; KOSDAQ open 773.06, high 808.92, low 773.06, close 808.89. Confirmed regular-session close data from our own collection. Opening-gap cross-checks: NewsPim·Aju Business Daily
Intraday chart — Reconstructed from the KOSPI’s five-minute regular-session path, with points placed at their actual times. Except for the four confirmed OHLC figures, intermediate values are shown as ranges; the 1 p.m. level of 5,717.19 comes from Aju Business Daily (1 p.m.)
Investor-group totals — Our KRX KOSPI collection at 3:38 p.m., including “other foreigners” in the foreign category. Stock-level net purchases were collected from KRX investor-by-stock data at 3:51 p.m. Other-corporation and Nextrade-inclusive totals: MoneyToday. Nextrade’s after-hours opening time: MoneyToday (Sept. 13). Amounts cross-checked at the ₩100m reporting level against Blockmedia. Other published comparisons: NewsPim·Asia Business Daily·EToday·NewsPim (10:26 a.m.). Intraday institutional, pension-fund, foreign and other-corporation flows: Opinion News·Aju Business Daily (1 p.m.). Stock-level ranking cross-checks: Pinpoint News (foreign investors)·Pinpoint News (institutions). Lee Kyung-min’s market commentary: NewsPim
Futures and program trading — KOSPI 200 futures by investor type: KRX, 3:49 p.m. Program-trading totals: 3:35 p.m. regular-session close. Five-session totals: KRX.
USD/KRW — Compared at 3:30 p.m. on both sessions. The Oct. 19 figure of ₩1,330.3 per dollar and the claim of its lowest level in roughly two years come from NewsPim. The Oct. 16 figure of ₩1,331.4 uses the same reference point as that day’s report.
Trading turnover — KOSPI ₩17.2174tn; Oct. 16 ₩20.0213tn; 0.75 times the Oct. 12–16 five-session average of ₩22.988tn. Figures from the 3:38 p.m. collection.
Short selling — KRX regular session plus Nextrade main market; 3:38 p.m. collection.
Market breadth — Final KRX counts of rising and falling stocks, with limit-up names tabulated separately from ordinary advancers.
Industry and theme indexes — Korea Exchange closing changes and constituent counts. Individual share returns cross-checked against Asia Business Daily·Pinpoint News (close)·License News. Market-cap gain shares are our own estimates using large-cap closing prices and market capitalization.
U.S. markets — Dow, S&P 500, Nasdaq and Philadelphia Semiconductor: Oct. 16 U.S. closing figures from our data collection. The Nasdaq’s −2.14% and Micron’s −5.63% came from TradingKey (regular-session close). Nvidia’s closing price: HeygoTrade. Other stock moves and weekly index returns: Financial News. The Philadelphia Semiconductor Index’s 443.93-point decline: Nasdaq index release. Background on the selloff, comparisons of the decline, CoreWeave, oil prices and the losing streak: Yonhap News (via Supple). U.S. stock-index futures: Jaekyung Ilbo·EconomyBlock. Oct. 19 oil prices and the Russian-sanctions suspension: TokenPost·HDFC Sky
Batteries — Original report: DigiTimes. Korean coverage and brokerage commentary: MoneyToday
Samsung Biologics — The court decision: Hankook Ilbo. The shares’ early reaction: Korea Economic Daily
Asia — Nikkei 225 and TOPIX: NewsPim. Chinese Q3 economic figures: MoneyToday
Calendar — U.S. earnings, the BOK policy meeting and PMI releases: Financial News (weekly outlook). Tesla earnings and Nvidia GTC: TokenPost. Samsung Biologics union schedule: Hankook Ilbo. SK Hynix buyback period: company disclosure.