Correction and editorial revision — 23 October 2026: This retrospective replaces the earlier mixed-time narrative with dated provider observations. The original regional-loss aggregate and fixed GDP-impact figures were not supported by a reproducible dataset. The earlier causal explanations and trading implications are withdrawn; their removal is not a finding that every cited event was false. The original input file is unavailable. The cutoff below is the calendar day before the original publication date, selected for this reconstruction; it is not a claim about what was known when the original article was written.
This archive review uses observations available in the retrieved daily history on or before 2026-03-23. Each market has its own closing time. The question is: Did a Korean Index Establish an Emerging-Market Collapse?
The measured comparison
KOSPI moved from 5,781.20 on 2026-03-20 to 5,405.75 on 2026-03-23: -6.49%. Its five-observation-interval return from 2026-03-16 was -2.60%. The last-day return and the longer-window return answer different questions; neither identifies a sector contribution. KOSPI history.
The S&P 500 returned +1.15% over 2026-03-20–2026-03-23, and the Nasdaq returned +1.38% over 2026-03-20–2026-03-23. The Korean daily percentage change minus the Nasdaq daily change is -7.88 percentage points. This is a comparison of separately timed intervals, not an estimate of how Korea reacted to that later US session. No broad emerging-market index was collected.
Reproducing the longer comparison
For KOSPI, the five-interval baseline is 5,549.85 on 2026-03-16; the endpoint is 5,405.75 on 2026-03-23. The calculation is (endpoint ÷ baseline − 1) × 100 = -2.60%. This uses the endpoints directly rather than adding rounded daily percentages. Five observations need not correspond to one calendar week when a market is closed.
Source-linked daily observations
| Series | Previous date | Previous value | Date | Value | Change | Time zone |
|---|---|---|---|---|---|---|
| KOSPI (^KS11) | 2026-03-20 | 5,781.20 | 2026-03-23 | 5,405.75 | -6.49% | Asia/Seoul |
| S&P 500 (^GSPC) | 2026-03-20 | 6,506.48 | 2026-03-23 | 6,581.00 | +1.15% | America/New_York |
| Nasdaq Composite (^IXIC) | 2026-03-20 | 21,647.61 | 2026-03-23 | 21,946.76 | +1.38% | America/New_York |
| US 10-year yield proxy (^TNX) | 2026-03-20 | 4.391 | 2026-03-23 | 4.334 | -5.7 bp | America/Chicago |
| WTI futures (CL=F) | 2026-03-20 | 98.32 | 2026-03-23 | 88.13 | -10.36% | America/New_York |
| Gold futures (GC=F) | 2026-03-20 | 4,574.90 | 2026-03-23 | 4,407.30 | -3.66% | America/New_York |
| USD/KRW (USDKRW=X) | 2026-03-20 | 1,489.84 | 2026-03-23 | 1,504.21 | +0.96% | Europe/London |
| USD/JPY (USDJPY=X) | 2026-03-20 | 157.92 | 2026-03-23 | 159.23 | +0.83% | Europe/London |
| VIX (^VIX) | 2026-03-20 | 26.78 | 2026-03-23 | 26.15 | -2.35% | America/Chicago |
Scope and limitations
Returns are calculated before rounding from Yahoo Finance daily history, not independently verified exchange settlement records. Index values are in points; the yield proxy is quoted in percent; currency quotes are local units per US dollar; gold and WTI futures are dollars per ounce and barrel. Futures-series changes can reflect contract rolls and are not a continuously held contract’s investment return. These are retrospective observations, not live prices or a reconstruction of every intraday quote available to the original author.
For the underlying method, see the trading-session and return guide. This page retains its original address for correction transparency. The title and text now reflect the narrower evidence available; the old URL wording should not be treated as a current claim. No trading instruction is retained.
