Today’s Calls
NVIDIA earnings aftermath meets a Friday open: semiconductor axis direction is today’s deciding variable
Friday, August 21 (2026) opens against a split backdrop: the Philadelphia Semiconductor Index (SOX)A U.S. index tracking the share prices of major semiconductor design and manufacturing companies, widely used as a leading indicator for Korean chip stocks.SK hynix and Samsung Electronics move closely with SOX direction; in the 2026 regime, same-day SOX-to-KOSPI correlation is among the inputs most frequently cited in morning forecasts. semiconductor index closed up +0.53% and the iShares MSCI South Korea ETF (EWY)A U.S.-listed exchange-traded fund that tracks the MSCI Korea Index, used as a real-time proxy for offshore investor sentiment on Korean equities.Because EWY trades in U.S. hours, its overnight move gives a pre-open read on how foreign investors are pricing the next Korean session. Korea ETF gained +2.14% on August 20 (2026), yet U.S. broad-market futures are down roughly 1% across the board and 10-year Treasury yields have rebounded to 4.70%.Today’s KOSPI closing level is not yet available — this is the pre-market edition published at 07:30 KST; the key question is whether foreign buyers extend the one-week net purchase of ₩3,474.6bn into a second week, or whether Friday’s historically elevated foreign selling probability (74% of 31 2026-regime Fridays) reasserts itself.
Today’s Calls
Where the day’s calls are placed by number — grading starts with the Early Session edition
Today’s forecasts (P1 KOSPI +0.3–+1.5%, P2 KOSDAQ flat) are live — August 20 (2026) went 3 for 12, with KOSPI and SK hynix direction both badly missed
On August 20 (2026), the morning edition carried 12 predictions and scored 3 correct — KOSPI direction was missed by 5.89%p and SK hynix by 16.13%p, both in the wrong direction; the August 20 lesson flagged that over-weighting SOX as an absolute leading indicator was the primary error.Today’s calls — P1: KOSPI +0.3–+1.5% (basis: SOX +0.53%, 2026-regime Friday up-probability 58%, foreign-turn first week) and P2: KOSDAQ flat -0.5–+0.5% (basis: Tesla signal weak, SOX linkage low) — will be scored in the post-close edition.
No individual stock predictions were filed for August 21 (2026) in the prediction record; sector-level calls were folded into the KOSPI and KOSDAQ market-level forecasts.
The world overnight — how the US session ended
A window on what happened in the US market overnight
Wall Street fell across the board Thursday as Treasury yields rebounded — Dow off 1.3%, Nasdaq down 1.0%, SOX up 0.53%
On August 20 (2026), the S&P 500 closed at 7,641.16 (-0.87%), the Nasdaq at 26,067.17 (-1.0%), and the Dow fell roughly 1.3% per event-calendar reporting; the SOX semiconductor index closed at 11,800.02, up +0.53% — diverging from the broader equity decline.The EWY Korea ETF, which reflects foreign-investor positioning, closed at 178.16 on August 20 (2026), up +2.14% — a signal that offshore participants were pricing in a recovery in Korean equities even as U.S. broad indices sold off.The Wall Street forecast scorecard stands at 15 hits out of 28 calls (54%) over the trailing 3-session horizon; in past 2026-regime sessions where SOX rose while broad U.S. indices fell, the subsequent KOSPI open direction has not been separately tabulated in the available data.
Korea–U.S. mutual following — overnight grading
A window on which market followed which
Overnight U.S. and Nikkei futures all negative, complicating the Korea-follows-U.S. pattern that held in 39 of 139 2026 YTD sessions
As of 05:00 KST on August 21 (2026), S&P 500 futures (ES) were at 7,667.75, down -0.97% from the August 20 (2026) 15:00 KST reference; Nasdaq 100 futures (NQ) stood at 29,317.25, down -1.2%; and Nikkei 225 CME futures (yen-denominated) were at 65,525, down -1.18%.These figures carry an estimated ±1-hour timing error given that hourly bar proxies are used in place of unavailable Korean overnight K200 futures data.
In 2026 year-to-date across 139 sessions, Korea followed the U.S. (same-direction, SOX ≥0.5%) in 39 cases, the U.S. followed Korea in 30, both moved together in 46, and neither tracked the other in 24.The foreign-investor-to-KOSPI same-day correlation in the current regime (2026) stands at 0.524, dropping to 0.145 one day later and 0.072 two days later — meaning same-day alignment is more reliable than lagged signals as a directional guide.
Overnight SOX ↔ same-day KOSPI in the same direction (|SOX| ≥ 0.5%) = Korea following · same-day KOSPI ↔ that night’s SOX in the same direction (|KOSPI| ≥ 0.5%) = the U.S. following
Night window —EWYofficial indicator
A window on what overnight futures foreshadow for the next day’s open
U.S. and Nikkei overnight futures all down roughly 1% — Treasury yield rebound cited as catalyst
As of 05:00 KST, S&P 500 futures stood at 7,667.75 (-0.97% from the August 20, 2026 15:00 KST bar), Nasdaq 100 futures at 29,317.25 (-1.2%), and Nikkei 225 CME yen-denominated futures at 65,525 (-1.18%); all three are proxies used in the absence of available Korean overnight K200 futures data, with an estimated ±1-hour bar-timing error.Overnight news flow attributes the U.S. equity decline to a rebound in Treasury yields — the 10-year reached 4.70% on August 20 (2026) — and Walmart’s U.S. comparable-sales growth coming in at its slowest pace in six years, adding a consumer-demand note to the macro backdrop ahead of today’s KOSPI open.
Pre-open08:00~09:00 — single-price auction (open/close)The single-price auction window (before the open and just before the close), where orders are pooled and matched at once.When large volume crowds into this window, a gap is created.forecast
A window on where the pre-open auction is pulling the opening price
SOX divergence and EWY +2.14% point to a semiconductor-led gap-up attempt — but U.S. futures slide and Friday foreign-selling pattern cut against it
The opening auction (08:30–09:00 KST) has not yet begun; the key observation point is whether the semiconductor axis — led by SK hynix and Samsung Electronics, which together accounted for ₩160.7bn of KOSPI turnover on August 21 (2026) — gaps up in line with the SOX’s +0.53% close, or is dragged lower by the Nasdaq’s -1.0% and Nikkei CME futures’ -1.18%.A secondary variable is the scale of forced-liquidation selling in the auction: the August 19–20 (2026) back-to-back selloff created margin-account stress whose residual pressure has not been confirmed in pre-market data, and the data as of 07:22 KST shows today’s investor flow figures at zero — pre-open, not yet populated.
Previous-Day Review
A window that retraces what happened in the previous session
August 20 (2026) prediction log: 3 of 12 calls correct — KOSPI and SK hynix direction both missed by wide margins
The Silmari Fear Gauge
A window measuring market anxiety through volatility, margin lending and short selling
Pre-market sentiment gauge score stands at 3 — market psychology data as of August 20 (2026)
The Crash-Precursor ScoreA composite score built from four sub-signals — ADR, Short-Selling SurgeDefined in this dataset as short interest rising 2.0× or more over five sessions on a stock with at least 50,000 shares short.In the 2026 regime, short-selling surges have been followed by a 5-day average return of -0.22% with a 50% down-probability, a meaningful drag versus the 2.76% regime baseline., sell-acceleration, and elevated sentiment — used to gauge the probability of a sharp near-term decline.A score of 3 today reflects two of four sub-signals active; the model’s full weighting methodology is described in the sentiment-gauge data. entering Friday, August 21 (2026) stands at 3 out of a possible maximum, driven by an Advance-Decline Ratio (ADR)The ratio of advancing stocks to declining stocks; a reading well below 1 signals broad-based selling pressure across the market.The ADR signal is one of the active sub-components in today’s crash-precursor score of 3. signal (U.S. session August 28, 2026 reading of -16.7%) and a short-selling surge signal (based on short-interest data through August 14, 2026, T+2 reflected).The composite sentiment gauge for today is not yet available — the weighted z-score model requires the full prior session’s inputs, which are collected after the close.
The short-selling surge base rate, defined as short interest rising 2.0× or more over five sessions on stocks with at least 50,000 shares short, shows the following in the current regime (2026–): across 117 events, the average 5-day return was -0.22% with a 50% down-probability, against a regime baseline of +2.76% — an excess of -2.98%p.In the prior regime (2018–2024), the same signal produced a -0.11% average 5-day return across 150 events with a 57% down-probability; in the 2025 transition period across 111 events the average was +1.35% with a 45% down-probability.
Today carries several overlapping inputs: U.S. Treasuries reversed higher overnight after a single-session pullback, Nasdaq futures are off -1.2% and S&P 500 futures -0.97% as of 05:00 KST, and the Nikkei 225 CME futures are down -1.18%.Given that multiple factors — U.S. rates, risk-off futures, a Friday session, and lingering forced-liquidation pressure from margin accounts stressed in the August 19–20 selloff — are all in motion simultaneously, the data does not support attributing any opening move to a single cause.The judgment is each reader’s own.
The won — the signal is the speed of the move, not its direction
A window on the pressure the won-dollar rate puts on foreign flows
Won steady at ₩1,395 per dollar as of August 20 (2026); yen-won cross at ₩877.17 per 100 yen
The won-dollar rate was quoted at 1,395.0 as of the most recent available reading (August 20, 2026), with the DXY dollar index at 98.87 — effectively unchanged from the prior session’s 98.84 (+0.01%).The yen-won cross stood at 877.17 per 100 yen; the 10-year U.S. Treasury yield was 4.70%, up 0.92% on the day, with overnight headlines citing a reversal in the prior session’s Treasury rally as a key driver of U.S. equity weakness.
The SilmariDecouplingWhen two markets that used to move together break apart and move separately.The wider the gap, the less any single index can tell you about the market.Gauge
A window on the pattern in the KOSPI–KOSDAQ decoupling
KOSDAQ closing level and change for August 21 (2026) are not yet available — market opens at 09:00 KST
Warning
A window flagging in advance where today’s session calls for caution
Crash-precursor score at 3; forced-liquidation pressure and Friday foreign-selling pattern warrant close monitoring at the open
The crash-precursor score entering today stands at 3, with two of four sub-signals active: the ADR signal (U.S. session, August 28, 2026) and the short-selling surge signal (short interest data through August 14, 2026).In the 2026 regime, Fridays have shown foreign net selling in 74% of 31 sessions, with an average foreign flow of -₩128.9bn and an average KOSPI daily swing of 3.88% — meaning Friday sessions tend to carry above-average volatility even in up-days.The August 19–20 (2026) selloff concentrated heavy stress on margin accounts; forced-liquidation (margin call) selling typically surfaces in the opening auction and the first 30 minutes of trading, though the actual scale of outstanding liquidation orders as of this morning has not yet been confirmed in the data.